High-Efficiency “Green” Quantum Dot Solar Cells

Abstract

Semiconductor quantum dots (QDs) are extremely interesting materials for the development of photovoltaic devices, but currently the present the drawback is that the most efficient devices have been prepared with toxic heavy metals of Cd or Pb. Solar cells based on "green" QDs totally free of Cd or Pbpresent a modest efficiency of 2.52%. Herein we achieve effective surface passivation of the ternary CuInS 2 (CIS) QDs that provides high photovoltaic quality core/shell CIS/ZnS (CIS-Z) QDs, leading to the development of high-efficiency green QD solar cells that surpass the performance of those based on the toxic cadmium and lead chalcogenides QDs. Using wide absorption range QDs, CIS-Zbased quantum dot sensitized solar cell (QDSC) configuration with high QD loading and with the benefit of the recombination reduction with type-I core/shell structure, we boost the power conversion efficiency of Cd-and Pb-free QDSC to a record of 7.04% (with certified efficiency of 6.66%) under AM 1.5G one sun irradiation. This efficiency is the best performance to date for QDSCs and also demonstrates that it is possible to obtain comparable or even better photovoltaic performance from green CIS QDs to the toxic cadmium and lead chalcogenides QDs.

Investigating the Control by Quantum Confinement and Surface Ligand Coating of Photocatalytic Efficiency in Chalcopyrite Copper Indium Diselenide Nanocrystals

“…[19][20][21][22][23] Moreover, these NCs display band-gaps of 4 <1.5 eV, which are in the visible region of the solar spectrum, and large absorption coefficients that are ideal for solar energy conversion. [24][25][26] In this context, there are few reports available demonstrating the photocatalytic activity of these NCs, and in all cases they were used in sensitizing wide band-gap semiconductors (e.g., ZnS, ZnO, and TiO 2 ).…”

Optimization of the recipe for the synthesis of CuInS2/ZnS nanocrystals supported by mechanistic considerations

“…They have promising applications in solar cells [2][3][4], heat electrical application [5], light-emitting diodes (LED) [6,7], sensors [8], fluorescent probes [9,10], biolabeling [11], anticounterfeiting [12], etc. However, the intrinsic toxicity of QDs containing heavy metals (e.g.…”

Enhanced light harvesting and electron collection in quantum dot sensitized solar cells by TiO2 passivation on ZnO nanorod arrays

“…Thus, we can conclude that the enhancement in ηcc owing to the incorporation of TiO2 helps to improve Jsc. The gain in ηcc is related to the charge recombination in solar cells [2,35].…”

“…7a shows the electron transport time (τd) for the blank and T-5 min cells. These two parameters can be calculated by the Equation (8) [35],…”