Sun, LeizhiHaight, RichardSinsermsuksakul, PrasertBok Kim, SangPark, HelenGordon, Roy2014-01-092013Sun, Leizhi, Richard Haight, Prasert Sinsermsuksakul, Sang Bok Kim, Helen H. Park, and Roy G. Gordon. 2013. Band alignment of SnS/Zn(O,S) heterojunctions in SnS thin film solar cells. Applied Physics Letters 103(18): 181904.0003-6951http://nrs.harvard.edu/urn-3:HUL.InstRepos:11500708Band alignment is critical to the performance of heterojunction thin film solar cells. In this letter, we report band alignment studies of SnS/Zn(O,S) heterojunctions with various compositions of Zn(O,S). Valence band offsets (VBOs) are measured by femtosecond laser pump/probe ultraviolet photoelectron spectroscopy (fs-UPS) from which conduction band offsets (CBOs) are calculated by combining with band gaps obtained by optical transmission/reflection measurements. The SnS/Zn(O,S) heterojunctions with S/Zn ratios of 0.37 and 0.50 have desirable small positive CBOs, while a ratio of 0.64 produces an undesirable large positive CBO. The results are consistent with the device performance of SnS/Zn(O,S) solar cells.en-USJournal Article2013-10-29Sun, Leizhi; Haight, Richard; Sinsermsuksakul, Prasert; Kim, Sang Bok; Park, Helen H.; Gordon, Roy G.2014-01-0910.1063/1.4821433