摘要
A low-cost and Mo(S,Se) 2 -free superstrate-type device structure is reported for the first time with the tunable band gap Cu 2 ZnSn(S 1-x Se x ) 4 nanocrystals. Using a facile hot-injection approach with only oleylamine reagent for synthesizing Cu 2 ZnSn(S 1-x Se x ) 4 nanocrystals with varied Se to (S + Se) ratio, the role of Se in Cu 2 ZnSn(S 1-x Se x ) 4 nanocrystals during the sulfurization step is systematically investigated. The loss of Sn is suppressed and the grain size is enlarged when the Se in Cu 2 ZnSn(S 1-x Se x ) 4 nanocrystals is replaced by S during the sulfurization. As a proof-of-concept, our superstrate-type architecture without using any binder in the ink exhibits V oc and FF comparable to the typical substrate-type device structure, in addition to its advantage of low cost. © The Royal Society of Chemistry 2013.