IMPROVED CDS BUFFER WINDOW LAYERS FOR THIN-FILM SOLAR-CELLS

A dip method to fine tune the absorbance of CdS thin polycrystalline f ilms using the size-dependent band gap of this semiconductor is presen ted. The method consists of preparing pure and anisotropically capped CdS nanocrystals in an organic solvent. These particles have the prope rty to self-connect on solid surfaces, leading to a textured homogeneo us coating. The film can be converted thermally into a pure CdS film. The band gap of the thin film can be fine tuned through the size of th e particle precursor or by controlling the conversion temperature duri ng the capping ligand thermolysis. These films should provide a good b uffer-window layer for thin film solar cells. In fact, the optical cut -off can be adjusted to avoid interfering with light collection. These films are compared with others made by classical chemical bath techni ques.