Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Field modulation in Na-incorporated Cu(In,Ga)Se2 (CIGS) polycrystalline films influenced by alloyhardening and pair-annihilation probabilities | Jeong et al. Nanoscale Research Letters 2011 6 581 http content 6 1 581 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Field modulation in Na-incorporated Cu In Ga Se2 CIGS polycrystalline films influenced by alloyhardening and pair-annihilation probabilities Yonkil Jeong1t Chae-Woong Kim2t Dong-Won Park1 Seung Chul Jung2 Jongjin Lee1 and Hee-Sang Shim1 Abstract The influence of Na on Cu In Ga Se2 CIGS solar cells was investigated. A gradient profile of the Na in the CIGS absorber layer can induce an electric field modulation and significantly strengthen the back surface field effect. This field modulation originates from a grain growth model introduced by a combination of alloy-hardening and pairannihilation probabilities wherein the Cu supply and Na diffusion together screen the driving force of the grain boundary motion GBM by alloy hardening which indicates a specific GBM pinning by Cu and Na. The pair annihilation between the ubiquitously evolving GBMs has a coincident probability with the alloy-hardening event. PACS 88. 40. H- 81. 10. Aj . Cd Keywords Cu In Ga Se2 solar cells grain growth model alloy hardening pair-annihilation Introduction Thin film solar cells are promising candidates for power generation and other integrated photovoltaic applications as part of an effort to develop new renewable energy technologies 1 2 . Specifically chalcopyrite semiconductor systems such as Cu In Ga Se2 CIGS have attracted a great deal of interest as potential absorber materials for thin film solar cells. In recent years the CIGS solar cells have demonstrated efficiencies of greater than 20 using three-stage co-evaporation methods 3 . One of the common methods for improving the performance of CIGS solar cells uses soda-lime glass SLG substrates in which the amount of Na incorporated into the CIGS absorber layer is on the order of at. 4 5 . Several models have been proposed that explain the effect of Na on .
