A Facile in Situ Synthesis Route for CuInS₂ Quantum-Dots/In₂S₃ Co-Sensitized Photoanodes with High Photoelectric Performance

Abstract

CuInS2 quantum-dot sensitized TiO2 photoanodes with In2S3 buffer layer were in situ prepared via chemical bath deposition of In2S3, where the Cd-free In2S3 layer then reacted with TiO2/CuxS which employed a facile SILAR process to deposit CuxS quantum dots on TiO2 film, followed by a covering process with ZnS layer. Polysulfide electrolyte and Cu2S on FTO glass counter electrode were used to provide higher photovoltaic performance of the constructed devices. The characteristics of the quantum dots sensitized solar cells were studied in more detail by optical measurements, photocurrent-voltage performance measurements, and impedance spectroscopy. On the basis of optimal CuxS SILAR cycles, the best photovoltaic performance with power conversion efficiency (η) of 1.62% (Jsc = 6.49 mA cm(-2), Voc = 0.50 V, FF = 0.50) under full one-sun illumination was achieved by using Cu2S counter electrode. Cu2S-FTO electrode exhibits superior electrocatalytic ability for the polysulfide redox reactions relative to that of Pt-FTO electrode.

Photocurrent enhancement of the CdS/TiO 2 /ITO photoelectrodes achieved by controlling the deposition amount of Ag 2 S nanocrystals

“…A typical strategy of the co-sensitization is employed to achieve a wide wavelength of light absorption. Co-sensitizing the TiO 2 photoelectrodes with different QDs with complementary absorption spectra has been reported previously [16,[26][27][28][29][30][31]. It is known that Ag 2 S with a narrow band gap of 0.9 to 1.05 eV and a larger absorption coefficient [32][33][34] can absorb light with longer wavelength (>500 nm).…”

Role of co-sensitization in dye-sensitized and quantum dot-sensitized solar cells

“…Here, the quasi-shell of CdS passivate the trap states of core CdTe nanoparticles as well as TiO 2 which reduces the recombination. Through improved QDs loading on the TiO 2 photoanode surface and optimizing its thickness, this was further improved as 6.76% [245,249]. With the optimization of alloyed CdSe x S 1−x nanoparticles layer thickness, a type II configuration of CdTe/CdSe x S 1−x QDs resulted 7.24% of efficiency which is the highest one [264] in comparing with the CdSe x Te 1−x -CdS sensitized solar cells [160].…”

“…With the optimization of number of cycles of SILAR deposition, Peng et al [190] obtained 2.93% of efficiency with the TiO 2 /3PbS/4CuInS 2 nanoparticles based solar cell. Wang et al fabricated SILAR and CBD methods based QDSSC having the architecture of FTO/TiO 2 /CuInS 2 QDs/In 2 S 3 /Electrolyte/Cu 2 S/FTO and achieved 1.62% efficiency with J sc = 6.49 mA cm −2 , V oc = 0.50 V, FF = 0.50 [249]. When visible light harvesting compound like CuInS 2 is coupled with the near infrared semiconductor like PbS, careful attention should be paid on their band alignment.…”

Room Temperature Synthesis of Nanocubic CuInSe2 Thin Films

“…During the last two decades immense progress has been achieved in the fabrication and manipulation of nanoscale crystallites and manipulation of the nanoscale crystallites and understanding of the size and shape dependent properties of the nanomaterial's [1,2].…”