title: Copper indium gallium selenide (CIGS) photovoltaic devices made using multistep selenization of nanocrystal films.
abstract: The power conversion efficiency of photovoltaic devices made with ink-deposited Cu(InxGa1-x)Se2 (CIGS) nanocrystal layers can be enhanced by sintering the nanocrystals with a high temperature selenization process. This process, however, can be challenging to control. Here, we report that ink deposition followed by annealing under inert gas and then selenization can provide better control over CIGS nanocrystal sintering and yield generally improved device efficiency. Annealing under argon at 525 °C removes organic ligands and diffuses sodium from the underlying soda lime glass into the Mo back contact to improve the rate and quality of nanocrystal sintering during selenization at 500 °C. Shorter selenization time alleviates excessive MoSe2 formation at the Mo back contact that leads to film delamination, which in turn enables multiple cycles of nanocrystal deposition and selenization to create thicker, more uniform absorber films. Devices with power conversion efficiency greater than 7% are fabricated using the multiple step nanocrystal deposition and sintering process.
authors: Department of Chemical Engineering, ‡Texas Materials Institute and Center for Nano- and Molecular Science and Technology, and §Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States.
authors: Taylor B
authors: TB
authors: Harvey
authors: Isao
authors: I
authors: Mori
authors: C Jackson
authors: CJ
authors: Stolle
authors: Timothy D
authors: TD
authors: Bogart
authors: David P
authors: DP
authors: Ostrowski
authors: Micah S
authors: MS
authors: Glaz
authors: Jiang
authors: J
authors: Du
authors: Douglas R
authors: DR
authors: Pernik
authors: Vahid A
authors: VA
authors: Akhavan
authors: Hady
authors: H
authors: Kesrouani
authors: David A
authors: DA
authors: Vanden Bout
authors: Brian A
authors: BA
authors: Korgel
mesh_terms: D003300:Copper / Q000737:chemistry*; D005708:Gallium / Q000737:chemistry*; D005898:Glass / Q000737:chemistry; D007204:Indium / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D012643:Selenium / Q000737:chemistry*; D012993:Solar Energy; D013696:Temperature
chemical_list: C517764:gallium selenide; D007204:Indium; D003300:Copper; D005708:Gallium; D012643:Selenium