In last few years, passivating charge carrier selective contacts have shown huge potential to overcome the optoelectronic losses of conventional p-n or p-i-n homojunction solar cells. In fact, today most of the high efficiency thin film solar cells incorporate carrier selective contact for improved performance. Conventionally, epitaxial III-V based thin film solar cells used wide band gap III-V materials (known as window layers) for passivation and carrier selectivity. However, in many cases, epitaxial growth of a doped wide band gap III-V material over the active region might be extremely challenging, particularly in nanowires. Therefore, we are looking into a new range of inorganic materials which can be used as electron/hole selective contact for thin film and nanowire III-V solar cells.
In this talk, I will present the work that I did during my PhD. I will show both theoretical and experimental results on ZnO as an electron selective contact for thin film and nanowire InP solar cells. I will also show results on the heterogeneous doping of CuI, a hole selective contact material, for its improved transparency, conductivity and long-term stability. Another key element of my dissertation is to transform an inefficient III-V absorber material into an efficient solar cell by using the nanowire architecture with radial charge carrier separation and an electron selective contact. Furthermore, I will also be showing theoretical results on how a high efficiency thin film solar cell can be fabricated with only 280 nm thick InP using carrier selective contacts and the concept of optical confinement.