This paper describes an investigation into the fabrication of absorber layer CuInSe2 films by co-evaporation process. And we used the stainless steel substrates to manufacture Al / ZnO:Al /ZnSe(CdS) / CuInSe2 / Mo /SiO2 / Stainless Steel(SS) flexible thin-film solar cell. In this study, we fabricated the main absorber layer CIS thin film by co-evaporation process including two steps, and CIS thin films parameters were estimated by sheet resistance. Under one-sun (AM1.5,100mW/cm2) conditions solar simulator, we compared the solar cell with different thickness of absorber layer, co-evaporation process and composition to improve solar cell performance. The energy conversion efficiency of the CIS thin-film solar cell (Al/ AZO/ CdS /CIS/Mo/ SLG) was 4.5¢M(Voc =0.38 V¡AJsc = 30.5 mA ¡AFF = 38.6 ¢M), flexible solar cell (Al/AZO/CdS/CIS/Mo/SiO2/SS) was 2.6%( Voc =0.2 V¡AJsc = 41.7 mA ¡AFF = 31.2 %).

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We had demonstrated that, by controlling and changing the temperature, reaction time and washing agents, the morphology and powder size of CuInSe2 can be altered considerably. CuInSe2 was synthesized by a solvothermal route as described by Y. Qian et al. By synthesizing nanorods, we can control the distance which the electrons are transported in hybrid solar cell with conjugated polymers. With the tuning of the band gap by controlling the nanorod length, we can increase the opportunity of orbits overlap between the CuInSe2 material and the PBO polymer matrix.. The synthetic temperature 1800C and reaction time 48 hrs are the best condition in our experiment. By using D.I water and ethanol as washing agents, we can find different morphology of spherical and nanowire. However, we fabricate hybrid solar cell by using these CuInSe2 powders in PBO conjugated polymers. By preparing hybrid solution in different concentration and controlling spin coating rate, we fabricate solar cells device successfully. From the I-V characteristics, we can get noticeable characteristics of diode. Then, we calculate the fill factor (F.F.) with the open-circuit voltage¡]Voc¡^and short-circuit current¡]Isc¡^

Thin films of CuInSe2 can be completely converted into CuInS2 after annealing in elemental sulfur vapor. In this thesis, the sulfide conversion process was done in an MBE chamber and the film was exposed to a heated sulfur source. Our experiments showed that complete conversion of a 1.0 £gm-thick CuInSe2 film into CuInS2 was achieved when the film was annealed in a sulfur beam flux of 4.5x1016 atoms/cm2-sec at 450¢J for 5 minutes. This is the shortest conversion time ever reported for the same annealing temperature. The speed of conversion process depended on sulfur vapor flux, film crystallinity, and original film composition. Among them, the film composition was the most important factor. The presence of Cu2Se phase in Cu-rich CuInSe2 film enhances the sulfide conversion process and confirmed by KCN etching of a Cu-rich sample. The role of Cu2Se phase in sulfide conversion was investigated. The sulfide conversion mechanism also presented in this work.

In this research, CuInSe2 thin film is grown at 350¢J low temperature by photo-assisted co-evaporation system to fabricate PI (polyimide) substrate flexible thin film solar cells. The low temperature growing CuInSe2 is analyzed by raman spectroscopy. Besides, sputtering Mo thin film on PI and CIS/Mo/PI contact properties are also researched for device fabrication. By studying the Ar pressure and Mo internal stress relationship during the deposition, the Mo layer has been fabricated with both low resistivity and good adhesion. The sheet resistance of Mo layer is 1.95 £[/¡¼ and shows ohmic contact with CuInSe2 at temperature below 350¢J. Raman spectroscopy shows that photo-assisted CuInSe2 has stronger and thinner A1 peak than which without light. Two-stage growing can help eliminating Cu2Se and background signals further. CA structure vibration modes are involved in the asymmetric A1 peak broadening. The SLG/Mo/CIS/CdS/ZnO:Al/Al structured device has open voltage, Voc = 0.320 V, short cut current, Isc = 3.61 mA, and solar cell fill factor, FF = 49.8 %. On the other hand, PI/Mo/CIS/CdS/ZnO:Al/Al structured device has open voltage, Voc = 0.318 V, short cut current, Isc = 2.71 mA, and solar cell fill factor, FF = 39.0 %¡C

Ce travail porte sur l'élaboration de cellules solaires CuInSe2 (CIS) en couches minces. Différentes techniques de croissance ont été mises en œuvre pour concevoir les matériaux composant la structure photovoltaïque. Ainsi, l'absorbeur CuInSe2 a été déposé par coévaporation sous vide (PVD) sur un substrat de verre recouvert de molybdène. Un système de détection de la lumière diffusée (SLS) par l'échantillon a été développé pour permettre le suivi in situ des transitions de phases pauvres/riches en cuivre. Cela a permis la croissance de couches de CuInSe2 à larges grains ainsi que le contrôle de leurs propriétés électro-optiques. La couche tampon de CdS a été obtenue par bain chimique (CBD) et son épaiseur optimisée par un procédé original où le substrat est directement chauffé par conduction. Enfin, la couche fenêtre de ZnO a été élaborée par divers procédés de croissance tels que l'électrodéposition (ED) et le dépôt par couches atomiques (ALD). Les propriétés structurales, optiques et électriques des différentes couches minces sont étudiées et mises en relation avec les performances photovoltaïques des cellules élaborées. / The aim of this work is the design of thin film CuInSe2 solar cells. Different growth techniques have been used to elaborate the layers involved in this photovoltaic stack. Thus, the absorber CuInSe2 has been deposited by coevaporation under vacuum (PVD) onto a molybdenum coated glass substrate. A scattered light monitoring system (SLS) has been designed in order to follow in situ the copper poor/rich phases transitions. It has led to the growth of CuInSe2 layers made of large crystalline grains with both high optical and electrical properties. The CdS buffer layer has been elaborated by chemical bath deposition (CBD) and its thickness has been tuned by an original process involving a conduction heated holder. Finally, the ZnO window layer has been grown by various techniques such as electrodeposition (ED) and atomic layer deposition (ALD). Structural, optical and electrical properties of all these thin films have been studied and correlated with the photovoltaic parameters of the solar cells elaborated.

We attempted to fabricate the CuInSe2:Sb thin-film solar cells with a Al/ZnO:Al(AZO)/ ZnSe /CuInSe2:Sb /Mo/soda-lime glass(SLG) structure. The growth of CuInSe2 film in the presence of Sb can effectively improve the surface morphology and benefit the growth of the device. A ZnSe buffer layer has been applied as an attractive alternative to a CdS buffer layer, thus eliminating environment from pollution. By varying the Ar pressure during the deposition, the Mo bilayer has been fabricated with both low resistivity and good adhesion. Currently the tensile stress was maintained below 100MPa, and the lowest sheet resistance achieved 0.205(£[/¡¼). The fabrication condition with a 5-cm sputtering distance could provide the lowest resistivity of 1.73¡Ñ10-3 (£[-cm) in the AZO thin-film that shows a transmittance of above 80¢Min the visible range. Applying the technology of optical lithography to deposit the Al metal front grid, the Al/ AZO ohmic contact resistance was improved. The energy conversion efficiency of the CIS thin-film solar cell (Al/ AZO/ ZnSe /CuInSe2 /Mo/ SLG) was 4.4¢M(Voc =0.41 V¡AI sc = 3.9 mA ¡AFF = 69 ¢M) by applying the irradiation with a solar simulator under one-sun (AM1.5, 100mW/cm2) conditions. However, the efficiency of CIS:Sb solar cell (Al/ AZO/ ZnSe /CuInSe2 :Sb /Mo/ SLG) was improved to to 6.0¢M(Voc =0.43 V¡AI sc = 5.15 mA ¡AFF = 68 ¢M). This result indicates that the CIS film growth with Sb can increase the short-circuit current.

Abstract The defect structure of CuMX2 (MºIn, Ga and XºS, Se, Te) was investigated. The defect concentrations were derived as a function of nonmolecularity( X) and nonstoichiometry( Y), and the carrier concentrations were calculated quantitatively using a theoretical defect model, which could be used to select the proper region of stoichiometry for device designs with specified carrier concentrations. The compensation reaction between dopants and intrinsic defects in CuMX2, compound semiconductors is quantitatively illustrated. If for a small increment of temperature the Fermi level EF is shifted by £GEF and the concentration of free majority carriers is increased by £Gn, then the ratio£Gn /£GEFis a measure of the defect-level concentration within£GEF. The electrical and optical properties of CuMX2 have been investigated using various types of electrically active intrinsic defects caused by deviations from the ideal stoichiometry of the compound. The defect complexes are formed by reactions among the impurity and native defects and/or among the native defects during crystal growth or during processing, and play a significant role in determining the characteristics and performance of devices by affecting lifetimes, degradation and breakdown etc.

In this paper, we use a room temperature processing system, Liquid Phase Deposition(LPD) method, to grow silicon dioxide. The advantages are cheap equipment, low temperature growth, and no thermal stress. The quality is good enough to be used in IC devices. To inverstigate the properties of silicon Dioxide, we have done different physical and chemical test, including AES,TEM,FTIR,P-etch rate. We used the high frequency C-V curve to study the interface properties. The leakage current help to clarify the film quality. Moreover, we also discuss the growth mechanism in order to more understanding of LPD method.