MANUFACTURE OF CDS-ZNS SOLID SOLUTION THIN FILM

摘要

PURPOSE:To improve conversion efficiency of a solar cell and to reduce its cost by laminating CdS and ZnS semiconductor thin films on a translucent board, exposing the laminated thin film with vapor of CdCl2 at a high temperature to activate it, and forming a solid solution. CONSTITUTION:A CdS laminated deposited film of undoped ZnS and doped with In is formed 1.1mum thick in entirety is formed, for example, at 8:2 of mol ratio of CdS and ZnS on a glass board. The quantity of In is 0 and 0.1-2mol% to the entirety of CdS, ZnS. This ZnS/CdS:In laminated film is heat treated in vapor of CdCl2 at 500-650 deg.C to form solid solution, simultaneously crystallized, and solid solution is easily formed by activating and heat treating a CdS-ZnS solid solution thin film having a wide band gap to be effectively added with In by an inexpensive depositing unit and a twice laminated deposited film of ZnS and CdS in vapor of CdCl2. Since the activated film is provided, defects are much less than those of a deposited film to provide high mobility and low resistance. The resistance can be further reduced by adding the In to effectively raise the efficiency of a solar cell.