Search

In this paper an easy and mild solution-processed method is introduced to prepare extra sodium (Na) doped Cu2ZnSnS4 (CZTS) films on Mo-coated soda-lime glasses. Through this method, the Na-doping concentration can be adjusted at the range from 3.9% to 5.4% continuously. By extra Na doping through solution process, the grain size of CZTS particles was enlarged apparently without introducing any impurity phase. More excitingly, the photoluminescence (PL) spectrum indicates that high Na-doping concentration has the strong suppression ability on the band-gap recombination of CZTS films. The carrier lifetime is promoted from 2.1 ns to 2.83 ns. CZTS thin film solar cell with 4.8% Na-doping concentration shows the best performance.

Earth-abundant and non-toxicity quaternary chalcogenide Cu2SrSnS4 is prepared by a facial ball-milling method. Its formation is revealed to be from the reaction between Cu2SnS3 and SrS at 600 °C. The bandgap of the prepared Cu2SrSnS4 film is speculated around 1.78 eV according to absorption test. The carrier lifetime of the prepared Cu2SrSnS4 film is about 2.06 ns. The photocurrent density of the Cu2SrSnS4 film is about 150 μA cm−2 at −670 mV bias vs Ag/AgCl electrode and it repeats after 10 cycles of 1000 s. Its notable generation of photocurrent and photoelectrochemical stability indicates its potential for photoelectric conversion application.

A Cu 2 ZnSnS 4 (CZTS) ultrathin film counter electrode (CE) was prepared in situ by the sol–gel method. As the film was only 200 nm thickness, it showed a degree of transparence. The dye-sensitized solar cell (DSSC) with the prepared CE was the bifacially active transparent cell, which exhibited η of 5.63% and 1.60% corresponding to front- and back-side illumination respectively. It showed improved performance compared to DSSC with Pt CE, Electrochemical impedance spectroscopy (EIS) and Cyclic voltammetry (CV) measurements indicated the CZTS ultrathin film CE had a superior electrocatalytic activity than Pt CE.