title: Suppressed Formation of Conductive Phases in One-Pot Electrodeposited CuInSe2 by Tuning Se Concentration in Aqueous Electrolyte.
abstract: The single-bath electrochemical deposition of CuInSe2 often leads to short-circuit behavior of the resulting solar cells due to the high shunt conductance. In this study, in an attempt to resolve this problem, the influence of the Se precursor concentration (CSe) on electrodeposited CuInSe2 films and solar cell devices is examined in the CSe range of 4.8 to 12.0 mM in selenite-based aqueous solutions containing Cu and In chlorides along with sulfamic acid (H3NSO3) and potassium hydrogen phthalate (C8H5KO4) additives. As CSe increases, the CuInSe2 layers become porous, and the grain growth of the CuInSe2 phase is restricted, while the parasitic shunting problem was markedly alleviated, as unambiguously demonstrated by measurements of the local current distribution. Due to these ambivalent influences, an optimal value of CSe that achieves the best quality of the films for high-efficiency solar cells is identified. Thus, the device prepared with 5.2 mM Se exhibits a power-conversion efficiency exceeding 10% with greatly improved device parameters, such as the shunt conductance and the reverse saturation current. The rationale of the present approach along with the physicochemical origin of its conspicuous impact on the resulting devices is discussed in conjunction with the electro-crystallization mechanism of the CuInSe2 compound.
authors: Photo-electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul 136-791, Korea.|Nanomaterials Science and Engineering, Korea University of Science and Technology , Daejeon 305-350, Korea.
authors: Byung-Seok
authors: BS
authors: Lee
authors: Photo-electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul 136-791, Korea.|Nanomaterials Science and Engineering, Korea University of Science and Technology , Daejeon 305-350, Korea.
authors: Sung-Yul L
authors: SY
authors: Park
authors: Photo-electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul 136-791, Korea.|Nanomaterials Science and Engineering, Korea University of Science and Technology , Daejeon 305-350, Korea.
authors: Jang Mi
authors: JM
authors: Lee
authors: Photo-electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul 136-791, Korea.
authors: Jeung-Hyun
authors: JH
authors: Jeong
authors: Photo-electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul 136-791, Korea.
authors: Jin Young
authors: JY
authors: Kim
authors: Department of Material Sciences and Engineering, Hanbat National University , Daejeon 305-719, Korea.
authors: Choong-Heui
authors: CH
authors: Chung
authors: Photo-electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul 136-791, Korea.|Nanomaterials Science and Engineering, Korea University of Science and Technology , Daejeon 305-350, Korea.|Green School, Korea University , Seoul 136-713, Korea.
authors: Doh-Kwon
authors: DK
authors: Lee
keywords: CuInSe2; conductive phases; electrodeposition; single-bath; thin-film solar cells