Oxide semiconductors have been envisaged to find applications in ubiquitous flexible electronics in daily life such as wearable electronic gadgets to offer novel user experiences. However, one of the bottlenecks to realise these applications is a lack of oxide-semiconductor components capable of wireless communications. As Bluetooth and Wi-Fi are the two dominant communication interfaces, fast enough front-end rectifiers must be developed to operate at their gigahertz (GHz) transmission frequencies. Furthermore, despite of significant developments of n-type oxide semiconductors in the last decade, widespread flexible electronics also requires high-performance p-type oxide semiconductors for use in complementary logic circuits. The objectives of this dissertation are to develop high quality Schottky barriers, achieve GHz speed Schottky diodes on rigid and flexible substrates, evaluate the noise properties of the Schottky diodes, develop p-type oxide semiconductor using sputtering technology, elucidate the hole transport mechanism in p type transistors, and demonstrate their potential applications such as radio receivers, complementary inverters and ring oscillators. First, indium gallium zinc oxide (IGZO) Schottky diodes were fabricated by using radio frequency magnetron sputtering. The oxygen content at the metal-IGZO interface was found to have a profound effect on the electrical performance. By introducing 3% O2 during the deposition of Pt or IGZO, the diodes exhibited excellent electrical properties without requiring any annealing treatment, thus allowing for the realisation of flexible IGZO Schottky diodes. The high-frequency properties of Pt-IGZO Schottky diodes on glass substrates were optimised by testing a range of IGZO thicknesses and diode active areas. The achieved highest cut-off frequency was beyond 20 GHz, which is to the best of our knowledge the fastest oxide-semiconductor device to date. On flexible substrates, the diodes also showed cut-off frequencies up to 6.3 GHz, well beyond the critical benchmark speed of 2.45 GHz for typical wireless communications. In order to assess the feasibility of using IGZO Schottky diodes in practical applications, measurements were taken to discern their low-frequency noise properties. In the as-deposited diodes, logarithmic dependence of the noise spectral density on the applied bias was observed, revealing that the dominant noise was generated in the space-charge region at low biases and in the series-resistance region at high biases, respectively. After annealing the diodes, very different noise mechanism was observed and the interface-trap-induced noise dominated the noise spectra. As one of the most promising p-type oxide semiconductors, SnO was also studied at low temperatures in this thesis. The experiment revealed that hole-transport mechanism was governed by either band conduction or variable range hopping in different temperature ranges. Finally, the potential for fully oxide-based electronics was demonstrated by an amplitude-modulation radio receiver comprising of an IGZO Schottky diode as the demodulator and a complementary ring oscillator based on IGZO and SnO transistors. In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of the University of Manchester's products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink.

Submitted by RAQUEL GALVAO BEZERRA (raquelgbezerra@gmail.com) on 2018-08-20T03:48:26Z No. of bitstreams: 1 Dissertação Corrigida Pela Banca Pós Defesa.pdf: 818740 bytes, checksum: a1ecb695e00e0b5ca1cb59e7fb07b2dd (MD5) / Approved for entry into archive by Sulamita Selma C Colnago null (sulamita@btu.unesp.br) on 2018-08-20T18:10:40Z (GMT) No. of bitstreams: 1 bezerra_rg_me_bot.pdf: 818740 bytes, checksum: a1ecb695e00e0b5ca1cb59e7fb07b2dd (MD5) / Made available in DSpace on 2018-08-20T18:10:40Z (GMT). No. of bitstreams: 1 bezerra_rg_me_bot.pdf: 818740 bytes, checksum: a1ecb695e00e0b5ca1cb59e7fb07b2dd (MD5) Previous issue date: 2018-07-17 / Objetivo: estabelecer valores-padrão para a aplicação do laser de diodo verde para o tratamento da triquíase menor e maior, assim como avaliar a taxa de sucesso com o tratamento realizado. Método: estudo prospectivo, com intervenção, realizado nos anos de 2016 e 2017, envolvendo portadores de triquíase com até 10 cílios alterados por pálpebra e que foram submetidos ao tratamento de termoablação dos cílios utilizando o laser de diodo Zeiss Visulas 532s com emissão de luz verde com comprimento de onda de 532nm. Os parâmetros utilizados foram definidos empiricamente, com tempo de aplicação de 200 ms, mira de 50 μm, intervalo de 150 a 200 ms, potência de 600 a 750 mW. O número de tiros aplicados foi definido pela a profundidade de ablação de 2,5 mm para cílios na pálpebra superior e 1,5 mm para os da pálpebra inferior. Os pacientes foram seguidos por até 15 meses, com reavaliações a cada 3 ou 4 meses. Dados demográficos, características da triquíase, bem como a taxa de sucesso no tratamento foram analisados estatisticamente. Resultados: Noventa e oito pacientes, 130 olhos, 135 pálpebras acometidas e 337 cílios triquiáticos foram estudados. A média de idade dos pacientes foi de 72,1 ± 12,3 anos, a maioria do sexo masculino (54,1%), da raça branca (98%), com triquíase menor (91,8%), unilateral (67,3%), sendo o olho direito (54,6%) e a pálpebra inferior (85,9%) os mais acometidos. A causa mais comum da triquíase foi a blefarite (64,3%), seguida de causas idiopáticas (15,3%). Não houve significância estatística na comparação das variáveis idade, sexo, raça, olho acometido e etiologia com a presença ou quantidade de cílios triquiáticos (p>0,05). Houve perda de seguimento em 11,2% dos pacientes. Utilizando os parâmetros citados, do total que permaneceu até o final do estudo, 69% obtiveram cura com 1 sessão, 13,8% com 2 e 1,1% com 3 ou 4 sessões. Considerando apenas os indivíduos que concluíram o tratamento e excluindo os que perderam seguimento, a taxa de cura foi de 85%. Houve redução de 2,5 para 0,7 cílios triquiáticos por pálpebra com apenas 1 sessão (p<0,001) e o número médio de tiros por cílio foi de 60,7. Pacientes submetidos a tratamentos prévios e com etiologia idiopática tiveram as maiores taxas de cura, 98,1% e 91,7% respectivamente. Conclusão: a termoablação com laser de diodo, usando os parâmetros observados neste estudo, é efetiva, apresentando altas taxas de cura no tratamento da triquíase. / Purpose: to establish standard parameters for laser application as well as to evaluate the success rate of treatment of minor and major trichiasis using green diode laser. Method: a prospective study with intervention, was carried out in the years 2016 and 2017, involving trichiasis carriers with up to 10 misdirected lashes per eyelid that were submitted to the thermoablation treatment of the misdirected lashes using Zeiss Visulas 532s diode laser with green light emission with wavelength of 532nm. The parameters used were empirically defined, with an application time of 200 ms, 50 μm size, range of 150 to 200 ms and power of 600 to 750 mW. The number of shots applied was defined by the depth of ablation of 2.5 mm for upper eyelid lashes and 1.5 mm for lower eyelid lashes. The patients were followed for up 15 months, with revaluations every 3 or 4 months. Demographic data, trichiasis characteristics, as well as the success rate with treatment were statistically analyzed. Results: ninety eight patients, 130 eyes, 135 affected eyelids and 337 trichiatic eyelashes were studied. The mean age was 72.1 ± 12.3 years old, the majority male (54.1%), Caucasian (98%), with minor trichiasis (91,8%) unilateral (67,3%), being the right eye (54,6%) and the lower eyelid (85,9%) the most affected. The most common etiology was blepharitis (64.3%), followed by idiopathic causes (15.3%). There was no statistical significance in the comparison of age, gender, race, affected eye, and etiology with the presence or quantity of the trichiatic eyelashes (p>0,05). Around 11.2% of patients lost follow-up. Using the mentioned parameters, of the total remaining until the end of study, 69% of patients achieving cure with 1 session, 13.8% with 2 and 1.1% with 3 or 4 sessions. Considering only the individuals who completed the treatment and excluding those who lost follow-up, the cure rate was 85%. There was a reduction of 2.5 to 0.7 trichiatic eyelashes per eyelid with only 1 session (p<0,001) e the average number of shots per eyelash was 60.7. Patients submitted to previous treatments and with idiopathic etiology had the highest cure rates, 98.1% and 91.7%, respectively. Conclusion: thermoablation with diode laser, using the parameters observed in this study, is effective, with high cure rates in the treatment of trichiasis.

No description available.

Cette thèse est dédiée à la modélisation et à la compréhension du fonctionnement de dispositifs organiques et plus particulièrement des diodes organiques. Tout d'abord, nous avons modélisé et analysé les caractéristiques courant-tension en mode statique de dispositifs planaire (diodes) ou longitudinaux (barreaux résistifs) à base de TIPS-pentacene. Nous avons pu ainsi expliquer l'origine du redressement en courant pour ce type de dispositifs à base de semi-conducteur non-dopé. L'aspect dynamique a ensuite été pris en compte, avec la proposition d'un modèle numérique et d'un modèle analytique simplifié du comportement en temporel de la diode, ce qui a permis de déterminer quels sont les paramètres physiques impactant la fréquence de coupure. Enfin, compte tenu de l'intérêt grandissant des photodiodes organiques, nous nous intéresserons également dans la dernière partie à la modélisation de la diode sous flux lumineux, pour des applications en tant que cellules solaire ou des photodétecteurs. Nous étudierons dans cette dernière partie l'impact des paramètres électriques et optiques du dispositif (épaisseur, mobilité, taux de dissociation des excitons, indice optique, etc.) sur les courants d'obscurité et sous illumination, et donc les rendements de conversion. / This report is dedicated to the modelling and understanding of organic devices functionement and more particularly to organic diodes. First, we modelled and analysed I-V caracterisations of planar (diodes) and longitudinal (resistive sticks) devices made with TIPS-pentacene. We could explain the reason of the rectifying behavior of devices based on undoped semiconductor. The dynamic aspect was then analysed with the help of a numerical model which was simplifyed in a semi-analytical one. This allowed us to find parameters who have an impact on the cutoff frequency. Finally, as there is a growing interest on organic photodiodes whose applications are organic photodetectors or solar cells, we modellised, in the last part, the impact of light on the functionnement of organic diodes. We studyed the impact of both electrical parameters and optical ones (thicknesses, mobility, dissociations rate of excitons, optical indexes, etc...) on dark current and under illumination.

A busca de melhores características elétricas, acompanhada de crescentes evoluções tecnológicas e novos materiais passivantes para junções semicondutoras vem sendo bastante pesquisados nas últimas décadas. Existem dois tipos de passivação: por filmes finos ou por filmes espessos. No primeiro caso são realizadas deposições de óxido de silício, carbeto de silício, nitreto de silício, enquanto que no segundo caso faz-se uso de materiais como borrachas de silicone ou vidros. A escolha entre filme fino e filme espesso está relacionada diretamente ao custo/benefício e as características do dispositivo final. Na indústria de semicondutores de potência opta-se pelos filmes espessos devido às grandes dimensões dos dipositivos e ao custo do processo empregado nas linhas de produção. Os passivantes mais utilizados em semicondutores de potência são borrachas de silicone e vidros. Os vidros inorgânicos são mais estáveis a temperaturas elevadas do que as borrachas de silicone. Neste trabalho procuramos desenvolver e controlar um processo de passivação a vidro em junções semicondutoras de dispositivos de potência para que seja usado numa linha de produção de diodos retificadores de alta estabilidade. Existem diferentes tipos de vidros para esta aplicação como os vidros de Al-Pb-B-Si e os vidros de Zn-B-Si. No presente trabalho foi realizada uma comparação entre a influência da composição química dos vidros, a granulometria do pó (frita) deste vidro, com a tensão de ruptura e corrente de fuga dos diodos levando em conta o rendimento do processo. Observou-se que fritas de vidro de Al-Pb-B-Si com granulometrias mais finas resultam em tensões de ruptura maiores com um rendimento de produção de até 33% superior aos demais casos. As correntes de fuga , à temperatura ambiente, para fritas de vidro de Zn-B-Si e Al-Pb-B-Si com diferentes granulometrias, se mostrou pràticamente a mesma. / The search for better electrical properties, new passivating materials for semiconductors junctions and the process of obtaining those ones have being studied intensively in the latest decades. There are two types of passivation layers: thick film and thin film. The first one is obtained by the deposition of silicon oxides, silicon nitride or silicon carbide, while in the second one is obtained through the application of silicon rubber or glass over the exposed juntion. The decision of using one or another depends on cost/benefit and desired electrical properties of the devices. In the semiconductor power industry the thick films are frequently used because the devices dimensions are large and the cost of these processes are cheaper than those of thin films. Silicon rubber and glass are widely used by this industry. The silicon rubbers are materials that show temperature resistance up to 2000C. The inorganic glasses are more stables at high temperatures. In this work we developed a process of glass passivation for power semiconductors devices, controlled this process and it is in use in a production line of a semiconductor power device industry. There are a few glasses for this application where the two more widely used are Al-B-Pb-Si glass and Zn-B-Si glass. In this work it was compared the influence of the glass chemical composition as well as frit grain size of the glass, over the breakdown voltage and leakage current of the devices. It was observed that glasses of Al-B-Pb-Si with smaller grain size gave better values of breakdown voltage with a production yield bigger up to 33%. It was obtained leakage current values of the same magnitude, at ambient temperature, for both kinds of glasses with different grain sizes and composition.

Orientador: Silvana Artioli Schellini / Resumo: Objetivo: estabelecer valores-padrão para a aplicação do laser de diodo verde para o tratamento da triquíase menor e maior, assim como avaliar a taxa de sucesso com o tratamento realizado. Método: estudo prospectivo, com intervenção, realizado nos anos de 2016 e 2017, envolvendo portadores de triquíase com até 10 cílios alterados por pálpebra e que foram submetidos ao tratamento de termoablação dos cílios utilizando o laser de diodo Zeiss Visulas 532s com emissão de luz verde com comprimento de onda de 532nm. Os parâmetros utilizados foram definidos empiricamente, com tempo de aplicação de 200 ms, mira de 50 μm, intervalo de 150 a 200 ms, potência de 600 a 750 mW. O número de tiros aplicados foi definido pela a profundidade de ablação de 2,5 mm para cílios na pálpebra superior e 1,5 mm para os da pálpebra inferior. Os pacientes foram seguidos por até 15 meses, com reavaliações a cada 3 ou 4 meses. Dados demográficos, características da triquíase, bem como a taxa de sucesso no tratamento foram analisados estatisticamente. Resultados: Noventa e oito pacientes, 130 olhos, 135 pálpebras acometidas e 337 cílios triquiáticos foram estudados. A média de idade dos pacientes foi de 72,1 ± 12,3 anos, a maioria do sexo masculino (54,1%), da raça branca (98%), com triquíase menor (91,8%), unilateral (67,3%), sendo o olho direito (54,6%) e a pálpebra inferior (85,9%) os mais acometidos. A causa mais comum da triquíase foi a blefarite (64,3%), seguida de causas idiopáticas (15,3%). Não hou... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Purpose: to establish standard parameters for laser application as well as to evaluate the success rate of treatment of minor and major trichiasis using green diode laser. Method: a prospective study with intervention, was carried out in the years 2016 and 2017, involving trichiasis carriers with up to 10 misdirected lashes per eyelid that were submitted to the thermoablation treatment of the misdirected lashes using Zeiss Visulas 532s diode laser with green light emission with wavelength of 532nm. The parameters used were empirically defined, with an application time of 200 ms, 50 μm size, range of 150 to 200 ms and power of 600 to 750 mW. The number of shots applied was defined by the depth of ablation of 2.5 mm for upper eyelid lashes and 1.5 mm for lower eyelid lashes. The patients were followed for up 15 months, with revaluations every 3 or 4 months. Demographic data, trichiasis characteristics, as well as the success rate with treatment were statistically analyzed. Results: ninety eight patients, 130 eyes, 135 affected eyelids and 337 trichiatic eyelashes were studied. The mean age was 72.1 ± 12.3 years old, the majority male (54.1%), Caucasian (98%), with minor trichiasis (91,8%) unilateral (67,3%), being the right eye (54,6%) and the lower eyelid (85,9%) the most affected. The most common etiology was blepharitis (64.3%), followed by idiopathic causes (15.3%). There was no statistical significance in the comparison of age, gender, race, affected eye, and etiology with... (Complete abstract click electronic access below) / Mestre

Laser Diodes (LD) have numerous applications for industry, military, medicine and communications. The first visible LD was invented in 1962 by Nick Holonyak, emitted at 710 nm (red). In 1990s, Shuji Nakamura invented the blue and green Light Emitting Diodes (LED) and later LDs. The production of LDs emitting between 532- 632 nm has been severely lagging behind the rest of the visible spectrum. Yellow and orange LDs are still not accessible due to the lack of successfully grown material with high optical efficiency. AlGaInP is the quaternary compound semiconductor used to grow green to red LEDs and red LDs. At a material composition that is supposed to lase below 630 nm, the optical efficiency becomes low due to the oxygen-related defects associated with high Al content. The quantum well intermixing (QWI) is a post-growth process that is applied to laser structure to tune the wavelength of laser. Until now, there are limited reports on successful intermixing of InGaP/InAlGaP laser structures while maintaining the crystal quality. In this work, we introduced a novel intermixing process that utilizes the high strain induced by the dielectric film during annealing to initiate the intermixing. We deposited SiO2 capping by plasma-enhanced chemical vapor deposition (PECVD) onto the InGaP/InAlGaP laser structure emitting at 635 nm, and then annealed the structure up to 950 Celsius for different periods of time, resulting in an astonishing 100 nm blueshift. This blueshift allowed us to produce an unprecedented shorter wavelength orange lasers emitting at 608 nm. For low degree of intermixing, we have noticed an increase in the intensity of the photoluminescence (PL) signal. The improvement in the PL signal was translated to a reduction in threshold current. We implemented the technique on an LED structure with Al-rich QWs emitting at 590 nm. Significant increase in the PL intensity (20 folds) was observed. By analyzing the improved structure, we observed reduction in oxygen contamination. This may represent a solution to the oxygen-related defect. The thesis opens the door for major steps forward in GaInP/AlGaInP structures for manufacturing efficient optoelectronic devices in the green, yellow and orange visible range.

Metal Insulator Metal (MIM) diodes that work on fast mechanism of tunneling have been used in a number of very high frequency applications such as (Infra-Red) IR detectors and optical Rectennas for energy harvesting. Their ability to operate under zero bias condition as well as the possibility of realizing them through printing makes them attractive for (Radio Frequency) RF applications. However, MIM diodes have not been explored much for RF applications. One reason preventing their widespread RF use is the requirement of a very thin oxide layer essential for the tunneling operation that requires sophisticated nano-fabrication processes. Another issue is that the reliability and stable performance of MIM diodes is highly dependent on the surface roughness of the metallic electrodes. Finally, comprehensive RF characterization has not been performed for MIM diodes reported in the literature, particularly from the perspective of their integration with antennas as well as their rectification abilities. In this thesis, various metal deposition methods such as sputtering, electron beam evaporation, and Atomic Layer Deposition (ALD) are compared in pursuit of achieving low surface roughness. It is worth mentioning here that MIM diodes realized through ALD method have been presented for the first time in this thesis. Amorphous metal alloy have also been investigated in terms of their low surface roughness. Zinc-oxide has been investigated for its suitability as a thin dielectric layer for MIM diodes. Finally, comprehensive RF characterization of MIM diodes has been performed in two ways: 1) by standard S-parameter methods, and 2) by investigating their rectification ability under zero bias operation. It is concluded from the Atomic Force Microscopy (AFM) imaging that surface roughness as low as sub 1 nm can be achieved reliably from crystalline metals such as copper and platinum. This value is comparable to surface roughness achieved from amorphous alloys, which are non-crystalline structures and have orders of magnitude lower conductivities. Relatively lower resistances of the order of 1 k ohm with a sensitivity of 1.5 V-1 have been obtained through DC testing of these devices. Finally, RF characterization reveals that input impedances in the range of 300 Ω to 25 Ω can be achieved in the low GHz frequencies (from 1-10 GHz). From the rectification measurements at zero bias, a DC voltage of 4.7 mV has been obtained from an incoming RF signal of 0.4 W at 2.45 GHz, which indicates the suitability of these diodes for RF rectenna devices without providing any bias. It is believed that with further optimization, these devices can play an important role in RF energy harvesting without the need to bias them.

In this work, the operating characteristics of quantum dot (QD) lasers with asymmetric barrier layers (ABLs) are studied. Several different cases are examined, in particular: 1) Effect of excited states on static and dynamic operating characteristics Within QDs, in addition to the lasing ground state, carriers can be captured into excited states, where they then decay into the ground state. This excited-state-mediated capture impacts the operating characteristics, limiting the maximum output power and modulation bandwidth. Three separate cases are considered: only indirect capture with electron-hole symmetry, both direct and indirect capture with electron-hole symmetry, and both direct and indirect capture of electrons but only indirect capture of holes. The impact of different parameters on the operating characteristics is studied, with values for maximizing the output power and modulation bandwidth being found. In addition, it is found that parasitic recombination in the active region in the space between QDs causes the output power to saturate at high injection currents for the cases of indirect capture for both electrons and holes and indirect capture for holes but direct and indirect capture for electrons, although the presence of the ABLs causes it to reach saturation at much lower currents. 2) QD laser with only a single ABL To be effective, the materials for ABLs must be carefully chosen to ensure that the band edges properly align to allow one carrier to enter the active region while preventing the other from overshooting it. Due to this requirement, it may arise that a suitable material only exists for one ABL but not the other. The performance of a QD laser with only a single ABL is considered and compared to a conventional QD laser. Specifically, the output power and characteristic temperature are calculated. While the single ABL laser only offers a negligible increase in output power compared to the conventional laser, it offers a considerable increase in characteristic temperature. 3) Analytical derivation of alpha factor in QD lasers with and without ABLs The alpha factor of a semiconductor laser describes the spectral linewidth broadening that occurs in semiconductor lasers due to changes in the refractive index due to the carrier density. While it has been studied experimentally, there has been little work done on deriving the alpha factor of QD lasers analytically. An expression for the alpha factor is found in this work using the real and imaginary parts of the complex susceptibility. For QD lasers with no inhomogeneous broadening, as well as ones with equilibrium filling of QDs with narrow line of QD size distribution, the alpha factor is independent of carrier density, and is therefore the same for any QD lasers, with or without ABLs. For QD lasers with equilibrium filling without a narrow line of QD size distribution, the alpha factor depends on carrier density, allowing for a potential difference between conventional and ABL QD lasers, however the difference between the two will be lessened. / Doctor of Philosophy / Semiconductor lasers are the most widely used laser, due in part to their ability to be controlled using electricity. Semiconductor lasers are used in a wide variety of consumer electronics, such as optical drives, as well as being used in fiber optic communications, where data is transmitted using the laser's light. Fiber optic communications transmit data by controlling the laser's output, where a high output (brighter light) represents a digital one, and a low output (dimmer light) represents a digital zero. Because semiconductor lasers can be directly controlled by changing the amount of current they receive, their output can easily be changed, allowing fast transfer of data. Despite their benefits, semiconductor lasers suffer from a drawback known as parasitic recombination. Parasitic recombination is a process that makes a significant portion of the current injected to generate useful light go to waste, which negatively impacts the laser's performance. One solution to parasitic recombination is the addition of asymmetric barrier layers (ABLs). By adding ABLs, parasitic recombination can be completely removed. In this work, several different cases of semiconductor quantum dot (QD) laser with ABLs are examined. Starting from a set of equations, the operating characteristics of the lasers in the different cases are found. First, the case of excited states is examined. The presence of excited states in semiconductor lasers impacts the rate that current can be converted to light, lowering their performance. By solving the starting rate equations, which describe the way different values change over time, the performance of the laser can be calculated. Specifically, the impact of several tunable parameters on the output power and modulation bandwidth are examined. The modulation bandwidth is how fast the laser output can be changed, which is equivalent to how fast data can be transmitted. Optimum values for the DC injection current, QD surface density (number of QDs per area), and laser cavity length are found.

Part A of 2 parts. / <p> This report is a study of the dynamic properties of semiconductor laser diodes. The measurement of some important laser diode parameters necessary for dynamic behaviour prediction is described. The relaxation oscillation behaviour for laser diodes pumped with nanosecond time scale current pulses is predicted using both an approximate analytic solution and computer simulations. This predicted behaviour is compared with experimental results. Dynamic experiments with an external cavity for extra optical feedback and a regenerative loop for optoelectronic feedback are also described and discussed. Details of the experimental setups and techniques used are given. </p> / Thesis / Master of Engineering (MEngr)