Kim, Jae-Yup Yang, Jiwoong Yu, Jung Ho Baek, Woonhyuk Lee, Chul-Ho Son, Hae Jung Hyeon, Taeghwan Ko, Min Jae 2024-01-20T06:00:38Z 2024-01-20T06:00:38Z 2021-09-04 2015-11 1936-0851 https://pubs.kist.re.kr/handle/201004/124851 Copper-indium-selenide (CISe) quantum dots (QDs) are a promising alternative to the toxic cadmium- and lead-chalcogenide QDs generally used in photovoltaics due to their low toxicity, narrow band gap, and high absorption coefficient. Here, we demonstrate that the photovoltaic performance of CISe QD-sensitized solar cells (QDSCs) can be greatly enhanced simply by optimizing the thickness of ZnS overlayers on the QD-sensitized TiO2 electrodes. By roughly doubling the thickness of the overlayers compared to the conventional one, conversion efficiency is enhanced by about 40%. Impedance studies reveal that the thick ZnS overlayers do not affect the energetic characteristics of the photoanode, yet enhance the kinetic characteristics, leading to more efficient photovoltaic performance. In particular, both interfacial electron recombination with the electrolyte and nonradiative recombination associated with QDs are significantly reduced. As a result, our best cell yields a conversion efficiency of 8.10% under standard solar illumination, a record high for heavy metal-free QD solar cells to date. English AMER CHEMICAL SOC COLLOIDAL NANOCRYSTALS SHAPE CONTROL CDSE PROSPECTS CUINSE2 SIZE MULTIPLICATION NANOPARTICLES ELECTROLYTE ENERGY Highly Efficient Copper-Indium-Selenide Quantum Dot Solar Cells: Suppression of Carrier Recombination by Controlled ZnS Overlayers Article 10.1021/acsnano.5b04917 1 ACS NANO, v.9, no.11, pp.11286 - 11295 ACS NANO 9 11 11286 11295 scie scopus 000365464800077 2-s2.0-84948406237 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Chemistry Science & Technology - Other Topics Materials Science Article COLLOIDAL NANOCRYSTALS SHAPE CONTROL CDSE PROSPECTS CUINSE2 SIZE MULTIPLICATION NANOPARTICLES ELECTROLYTE ENERGY quantum dot-sensitized solar cells copper-indium-selenide ZnS overlayers heavy metal-free recombination control