This thesis investigates novel hole extraction interfaces and series interconnects for applications in organic photovoltaics, specifically in single junction solid-state dye-sensitized solar cells (DSSCs) and tandem DSSC/polymer bulk heterojunction solar cells. Improvements in hole extraction and device performance by using materials compatible with scalable deposition methods are presented, including tungsten- and molybdenum-disulphide (WS₂ and MoS₂), and p-type doped spiro-OMeTAD (2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)9,9'-spirobifluorene) nanoparticle dispersions. WS₂ and MoS₂ hole extraction layers increase averaged short circuit currents by 20% and 16% respectively, and power conversion efficiencies by 19% and 14% respectively when compared with control devices. Similarly, doped spiro-OMeTAD nano-particle layers improved short circuit current densities by 32% and efficiencies by 9%. Tandem device interconnects using these novel hole extraction formats have been fabricated, but although devices did exhibit rectification, overall performance was poor. Possible reasons for their limited success have been analysed. Dye-sensitized solar mini-modules are also reported. In order to assure the scalability of DSSC technology, these larger area devices were constructed using doctor blade coating to deposit the hole transporter material. As well as achieving a respectable maximum power conversion efficiency of 2.6%, it has also been shown that the extent to which hole transporter infiltrates the mesoporous photoanode of these devices may be tuned by altering substrate temperature during deposition. It was found that an optimal coating temperature of 70 degrees C produced the best efficiency, with a corresponding pore-filling fraction of 41%.

The perceived battery capacity of battery-powered devices can be increased by harvesting energy from readily available sources. Third generation solar cells are a good candidate for this purpose since they can be integrated with these battery-powered devices and harvest power from diffused light. For a single third generation solar cell to be useful in the context of charging a Lithium based battery, the voltage must be increased tenfold. To increase this perceived battery capacity as much as possible, efficiency is crucial. In this thesis, DCDC converter topologies and designs are studied from a system design perspective. The specifications of a converter suitable for interfacing Dye-Sensitised Solar Cells with Lithium batteries are described and a market research is conducted based on those specifications. A comparison of the available commercial solutions is presented, highlighting the most suitable options. However, none of the commercial solutions met the specifications to the full extent. The design process of two DC-DC converters is presented, one is a Boost converter operating in Continuous Conduction Mode and the other is a Boost converter operating in Discontinuous Conduction Mode. A comparison of the two designs highlights the advantages of operating the Boost converter in Discontinuous Conduction Mode when interfaced with a Dye-Sensitised Solar Cell. The design with a Boost converter operating in Discontinuous Conduction Mode has an efficiency of 80.3 % and is capable of tracking the Maximum Power Point of the Dye-Sensitised Solar Cell. / Den uppfattade batterikapaciteten hos batteridrivna enheter kan ökas genom att skörda energi från lättillgängliga källor. Tredje generationens solceller är en bra kandidat för detta ändamål eftersom de kan integreras med dessa batteridrivna enheter och skörda ström från spritt ljus. För att en enda tredje generationens solcell ska vara användbar i samband med laddning av ett litiumbaserat batteri måste spänningen ökas tiofaldigt. För att öka denna uppfattade batterikapacitet så mycket som möjligt är effektiviteten avgörande. I denna avhandling studeras topologier och strategier för DC-DC-omvandlare från ett systemdesignperspektiv. Specifikationerna för en omvandlare som är lämplig för att ansluta Dye-sensitized solceller med litiumbatterier beskrivs och en marknadsundersökning utförs utifrån dessa specifikationer. En jämförelse av de tillgängliga kommersiella lösningarna presenteras och belyser de lämpligaste alternativen. Ingen av de kommersiella lösningarna uppfyllde emellertid specifikationerna i sin helhet. Designprocessen för två DC-DComvandlare presenteras, en Boost-omvandlare som arbetar i kontinuerligt ledande läge och en Boost-omvandlare som arbetar i diskontinuerligt ledande läge. En jämförelse av de två designerna belyser fördelarna med att driva Boost-omvandlaren i diskontinuerligt ledningsläge när den kopplats till en färgkänslig solcell. Konstruktionen med en Boostomvandlare som arbetar i diskontinuerlig ledningsläge har en effektivitet på 80.3 % och kan spåra den maximala effektpunkten för solcellen.