Up-Scaling Process of Thin Film Silicon Solar Cells and Modules in Industrial PECVD KAI Systems

Abstract

Amorphous silicon p-i-n solar cells and modules have been developed in small R&D KAI reactors. Test cells of 0.25 mm thick i-layer exceed 10 % initial efficiencies and stabilized ones of 8.2 %. The a-Si:H deposition process is successfully transferred to industrial size substrates of 1.4 m 2 area resulting in initial module powers of 106.4 W using a commercial TCO front AFG and, recently, 104.1 W using in-house developed LPCVD front ZnO. For both modules our in-house LPCVD ZnO has been applied as back contact. The former large-area module passed successfully the damp-heat test. Entirely microcrystalline p-i-n cells with an efficiency of 8.5 % could be prepared in a single-chamber KAI-S reactor. Micromorph tandems resulted in initial cell efficiencies of 10.7 %, whereas minimodules lead to initial aperture efficiencies of 10.2 %.

Large Area a-Si/μc-Si Thin Film Solar Cells

“…Volume production of a-Si based solar panels started after the year 2000 with the introduction of large-area chemical vapor deposition (CVD) process at these companies: Sharp Corporation, United Solar Ovonic, Kaneka, Mitsubishi Heavy Industries, Ltd, etc. The true burst of Si thin film solar cells, on the other hand, came after 2007 with the "turnkey" (ready to use) thin-film solar manufacturing equipments introduced by Unaxis SPTec (later Oerlikon Solar) (Meier et al 2007) and Applied Films Gmbh & Co. (later part of Applied Materials Inc.) (Repmann et al 2007). The idea is that instead of developing the film deposition and module manufacturing technologies by self, the would-be solar maker can buy the full set of equipments together with the process recipes, and start manufacturing panels with relative ease.…”