Large‐Scale, Surfactant‐Free Solution Syntheses of Cu(In,Ga)(S,Se)₂ Nanocrystals for Thin Film Solar Cells

Abstract

Large‐scale (as much as 200 g in a batch) and surfactant‐free syntheses of the CuInxGa1–xSe2 and the CuInxGa1–xS2 nanoparticles were investigated by employing a sonochemical process under ambient conditions. This synthetic approach eliminates the need for organic stabilizers, which may act as an insulator in the final device, and reduces the number of reaction steps for synthesis of high‐quality CISe nanocrystals. We also demonstrate the solution‐based fabrication of the thin film photovoltaic devices with a conversion efficiency of 2.62 % by using nanocrystal‐based inks. The device was fabricated with 2 μm of a CIGS absorber layer on Mo‐coated soda lime glass, 70 nm of a chemical‐bath‐deposited CdS layer, 100 nm of an intrinsic ZnO layer, followed by 800 nm of a Al‐doped ZnO layer. Finally, a patterned Ag (200 nm) grid was deposited on the top of the device. The current results offer a promising alternative for solution‐based CIGSe thin film solar cells, with a higher efficiency.

Sonochemistry: Science and Engineering

“…However, with the emerging of materials such as graphene, nanotubes etc., which are good transparent conductors, efficiency of DSSCs can be further improved. In addition to DSSC and use of Zn and Ti, Cu based hetero structures have also been used in making solar cell -thin film solar cell (TFSC) that offer higher stability than DSSC but with a slight compromise in efficiency, lowering as much as 2.62% [213]. Use of ultrasound for the synthesis of Cu(In or Ga)(S or Se) 2 hetero structure, expedites the process and also obviates the common need of stabilizers.…”

Properties of Sonochemically Prepared CuInxGa1-xS2and CuInxGa1-xSe2

“…Recently [3], these nanomaterials have been surfactant-free synthesized sonochemically at 373 K. This synthetic approach eliminates the need for organic stabilizers, which may act as insulators in the nal photovoltaic device, and reduces the number of reaction steps for synthesis of highquality Cu(In,Ga)(S,Se) 2 nanocrystals. With regard to the nanocrystal ink, a simple process for solar cell fabrication by using a non-vacuum technique based on the CIGSe absorber layer was presented [3].…”

“…The aim of this paper was to synthesize the CIGSe and CIGS nanomaterials using ultrasound radiation at lower temperature than it was done in [3]. The other goal of this paper was to use the frequency-dependence method of photoconductivity investigations [4,5] to determine carrier lifetimes in the CIGSe nanomaterials.…”

Synthesis of CuInS2 by Sulfide Ion‐Exchange of CuIn(OH)5 Precursors

“…[5][6][7] This method has some disadvantages, including high-temperature processing, long-reaction time, and surface modification to remove organics. 7,8 Herein, we report a facile synthetic route to obtain CuInS 2 semiconductor by Na 2 S anion-exchange with bimetallic hydroxide precursor in aqueous solution at room temperature. The bimetallic CuIn(OH) 5 precursor was prepared from two starting materials, chloride and nitrate salts, because the properties of the final product depend on the types of soluble metal salt anions.…”