Sb2Se3 thin-film solar cells via low-temperature thermal evaporation technique.

There has been a lot of anomalies in the climate in recent years. The situation is getting worse with every passing day, this alarming situation is the talk of the town amongst the world’s scientific community. There has been a consistent search for cleaner and sustainable source of energy which can replace the conventional fossil fuel. To this date renewable energy such as solar, wind, ocean, hydrothermal are in application. Among these, solar photovoltaic (PV) is the most effective and widely used one due to its abundant availability and zero contribution to pollution. In order to harness this energy conventional wafer based solar cells were used which have high cost of production and a longer by back time. Second generation thin film based solar cells are the talk of the time as they can be produced with less consumption of material and energy and hence are economical. Three materials are currently in the market; they are amorphous silicon (a-Si), cadmium telluride (CdTe) and copper indium gallium selenide (CIGS). Amongst them, CIGS has shown the highest efficiency of above 20% in laboratory scale, while CdTe has the highest market share. A drawback with CIGS and CdTe technologies is the use of scarce and expensive elements indium and tellurium. It is therefore clear that these are issues which are of concern for long-term availability of CdTe and CIGS. It is in this context; investigations have been initiated all over the world for an alternative, abundant and non-toxic absorber material. Antimony chalcogenide (Sb2Se3, Sb2S, Sb2(S,Se)3) are promising absorber materials for thin film photovoltaic cells due to their high absorption coefficient (>104cm-1) and optimum direct band gap (~1.2eV). Sb2Se3 has excellent optoelectronic properties with low processing temperature these are key factors responsible for the growing interest within the PV community. The best performing cells have reached above 10% till date. This thesis entitled “Sb2Se3 thin film solar via low thermal evaporation technique” is a detailed study of the fabrication of Sb2Se3 absorber films by low temperature thermal evaporation technique. Films have been as deposited, vacuum annealed as well selenized and studied in detail in this thesis. The studies included in the thesis are divided into eight chapters.