Keywords: TCO coatings, APCVD, solar cells, F-doped SnO2, optical absorbance, transparent conducting oxides, photovoltaics, chemical vapour deposition, CVD, nanotechnology, tin oxide
Optimum performance solar cells using atmospheric pressure chemical vapour deposition deposited TCOs
High performance transparent conducting oxides (TCOs), have significance for optimising PV performance. We have developed an advanced atmospheric pressure chemical vapour deposition process, by applying fast experimentation and using a combinatorial chemistry approach to aid the studies. The deposited films were characterised for crystallinity, morphology (roughness), haze and resistivity to aid optimisation of material suitable for solar cells. Optical measurements on these samples showed low absorption losses, less than 1% around 500 nm for one pass, which is much lower than those of industrially available TCOs. Selected samples were then used in manufacture of single junction a-Si : H solar cells, which showed high initial solar energy conversion efficiencies up to 9.3% and high short circuit current densities of 15 mA/cm². Compared with (commercially available) TCO CVD coated glasses, these TCO coatings show excellent performance resulting in a high quantum efficiency yield for a-Si : H solar cells.