Open AccessHigh-efficiency one-sun photovoltaic module demonstration using solar-grade CZ silicon. Final report
Author(s) -
J.M. Gee
Publication year - 1996
Language(s) - English
Resource type - Reports
DOI - 10.2172/399682
Subject(s) - fabrication , common emitter , photovoltaic system , silicon , materials science , solar cell , optoelectronics , work (physics) , engineering physics , crystalline silicon , thermal , nanotechnology , mechanical engineering , electrical engineering , engineering , physics , medicine , alternative medicine , pathology , meteorology
This work was performed jointly by Sandia National Laboratories (Albuquerque, NM) and Siemens Solar Industries (Camarillo, CA) under a Cooperative Research and Development Agreement (CRADA 1248). The work covers the period May 1994 to March 1996. The purpose of the work was to explore the performance potential of commercial, photovoltaic-grade Czochralski (Cz) silicon, and to demonstrate this potential through fabrication of high-efficiency cells and a module. Fabrication of the module was omitted in order to pursue further development of advanced device structures. The work included investigation of response of the material to various fabrication processes, development of advanced cell structures using the commercial material, and investigation of the stability of Cz silicon solar cells. Some important achievements of this work include the following: post-diffusion oxidations were found to be a possible source of material contamination; bulk lifetimes around 75 pts were achieved; efficiencies of 17.6% and 15.7% were achieved for large-area cells using advanced cell structures (back-surface fields and emitter wrap-through); and preliminary investigations into photodegradation in Cz silicon solar cells found that oxygen thermal donors might be involved. Efficiencies around 20% should be possible with commercial, photovoltaic-grade silicon using properly optimized processes and device structures