Inexpensive methodology to prepare TiO₂/CuInS₂hetero-junctions for photovoltaic applications

Abstract

TiO 2 and CuInS 2 (CIS) hetero-junctions were prepared using low-cost, solution-based techniques. Using conducting glass (FTO) as substrate, a thin film of TiO 2 and an ultrathin film of In S that acts as buffer layer were deposited by spray pyrolysis. CIS was electrodeposited on top of this duplex layer, at pH 8, room temperature and at constant potential. A solar cell consisting of FTO/TiO 2 /In 2 S 3 /CIS/graphite was built in superstrate configuration. Morphology, thickness, crystalline structure and chemical composition were analyzed by electronic microscopy, X-Ray diffraction and Raman spectroscopy. CuInS 2 films were found to be crystalline with a thickness of 0.4 μm and showed good adhesion. Current-voltage curves in the dark and under illumination proved that the solution-based and vacuum-free deposition of these materials has promising photovoltaic applications. Different thicknesses of the buffer layer were evaluated and the best results were found for In 2 S 3 layers deposited with 6 spray cycles. The best solar cell performance showed an efficiency equal to 3.3 % with a V oc = 0.583 V, J sc = 17.7 mA/cm 2 , FF = 0.32.

Highly‐efficient superstrate Cu2ZnSnS4 solar cell fabricated low‐cost methods

“…For these reasons, a CuInS 2 (CIS) solar cell fabricated using identical procedures those in the CZTS solar cell has been included in Fig. and Table for comparison . The thickness ( d ) of both absorber layers are similar and less than 500 nm.…”

“…The films were deposited applying a fixed potential ( E =–1.05 V vs. SCE) during 15 min at room temperature with a slowly stirring using as potentiostat a Solartron Instrument 1280B. Then, the films were annealed in sulfur vapor atmosphere (sulfur powder) at 580 °C for 90 min using a purpose built reactor . The morphological and structural characterization of CZTS films onto FTO/TiO 2 /In 2 S 3 are presented as Supporting Information (Figs.…”

Effect of supporting electrolyte concentration on one-step electrodeposited CuInS2 films for ZnS/CuInS2 solar cell applications

“…This compound also has good radiation stability and environmental compatibility, which should allow CIS photovoltaic devices to maintain performance even in adverse conditions [12]. So far, several methods, such as co-evaporation, sputtering, spray pyrolysis and electrodeposition, have been used for the fabrication of CIS thin films [13][14][15]. Among these methods, co-evaporation and sputtering are the most used to synthesize CIS films for TFSC applications.…”