Aqueous solution-processed off-stoichiometric Cu–In–S QDs and their application in quantum dot-sensitized solar cells

Abstract

Off-stoichiometric CuInS2 quantum dots (CuInS2, a mixture of In2S3/CuInS2, and a Mn-doped mixture of In2S3/CuInS2) were prepared in a one-pot reaction, and the corresponding sensitized solar cells exhibit promising photovoltaic performances.

In Situ Microwave‐Assisted Fabrication of Hierarchically Arranged Metal Sulfide Counter Electrodes to Boost Stability and Efficiency of Quantum Dot‐Sensitized Solar Cells

“…The integral J SC values for CuS, NiS, and PbS were 20.42, 18.83, and 18.64, respectively, and followed the trend extracted from J–V curves. The estimated J SC values are lower than the measured values from J–V curves due to the lower light intensities used in the IPCE measurement, the effect of high chopping frequency on the IPCE spectrum, and the absence of bias light . As regards the NiS and PbS based QDSSCs, the responses are comparable with a slightly higher value for NiS CEs that is also consistent with the variation in their PCEs.…”

“…The clear lattice pattern features crystalline nature of CuInS 2 /In 2 S 3 with the two crystal structures of CuInS 2 and In 2 S 3 having the lattice spacing of 0.319 and 0.164 nm, respectively. In our previous work, we reported the synthesis and characterization of CuInS 2 /In 2 S 3 photoelectrode and demonstrated that the In 2 S 3 buffer layer decreases the recombination losses at CuInS 2 and TiO 2 junction . Introduction of this layer also benefited the band alignment at the TiO 2 /CuInS 2 interface.…”

“…As shown, the solar cell with the CuS CE exhibits maximum PCE = 8.32 % with J SC = 26.67 mA cm −2 , V OC = 652 mv, and FF = 47.8 %. In the case of the spin‐coated Cu 2 S as a CE in the QDSSC with the Cu–In–S photoanode, the cell efficiency of 7.53% ( J SC = 25.2 mA cm −2 , V OC = 630 mV, FF = 47.3%) was obtained . As shown in Figure S7 in the Supporting Information, the Cu 2 S nanoflakes with 2D structure are likely to be more desirable for catalytic application because of higher surface energy.…”

“…Synthesis of CuInS 2 /In 2 S 3 QDs : The CuInS 2 /In 2 S 3 QDs were synthesized in an aqueous solution via a microwave‐assisted using a slight modification of previously described procedures . Briefly, CuCl 2 (1.25 × 10 –2 mmol), InCl 3 (5.00 × 10 –2 mmol), and l ‐cysteine (8.8 × 10 ––2 mmol) were dissolved in 20 mL deionized (DI) water, followed by adjusting the pH at ≈9.0 using NaOH.…”

Quantum dot-sensitized solar cells

“…198,211,216,[243][244][245][246][247][248] Up to date, the reported highest PCE with use of aqueous QD sensitizer under the irradiation of one full sun light is 8.0%, and a PCE of 8.15% was also obtained but under light intensity of 30 mW cm -2 . 249,250 It is noted that the aqueous QD sensitizers were mostly concentrated on CuInS2, and CdTe based QDs due to the relatively matured aqueous synthesis methods for these two kinds of QDs. A variety of binary QDs, such as InP, 95,209 InAs, 96 CdS, 146,202,251,252 CdSe, 99,100,110,200,203 CdTe, 206,253 PbS, 127,207,213,[254][255][256][257][258][259] Ag2S, 169,210,[260][261][262] etc.…”