title: Cation/Anion Substitution in Cu2ZnSnS4for Improved Photovoltaic Performance.
abstract: Cations and anions are replaced with Fe, Mn, and Se in CZTS in order to control the formations of the secondary phase, the band gap, and the micro structure of Cu2ZnSnS4. We demonstrate a simplified synthesis strategy for a range of quaternary chalcogenide nanoparticles such as Cu2ZnSnS4(CZTS), Cu2FeSnS4(CFTS), Cu2MnSnS4(CMTS), Cu2ZnSnSe4(CZTSe), and Cu2ZnSn(S0.5Se0.5)4(CZTSSe) by thermolysis of metal chloride precursors using long chain amine molecules. It is observed that the crystal structure, band gap and micro structure of the CZTS thin films are affected by the substitution of anion/cations. Moreover, secondary phases are not observed and grain sizes are enhanced significantly with selenium doping (grain size ~1 μm). The earth-abundant Cu2MSnS4/Se4(M = Zn, Mn and Fe) nanoparticles have band gaps in the range of 1.04-1.51 eV with high optical-absorption coefficients (~104cm-1) in the visible region. The power conversion efficiency of a CZTS solar cell is enhanced significantly, from 0.4% to 7.4% with selenium doping, within an active area of 1.1 ± 0.1 cm2. The observed changes in the device performance parameters might be ascribed to the variation of optical band gap and microstructure of the thin films. The performance of the device is at par with sputtered fabricated films, at similar scales.
authors.affiliation: IITB-Monash Research Academy, IIT Bombay, Powai, Mumbai, 400076, India.|Department of Physics, IIT Bombay, Powai, Mumbai, 400076, India.
authors.forename: Balakrishna
authors.initials: B
authors.lastname: Ananthoju
authors.affiliation: Centre for Research in Nanotechnology and Science (CRNTS), IIT Bombay, Powai, Mumbai, 400076, India.
authors.forename: Jeotikanta
authors.initials: J
authors.lastname: Mohapatra
authors.affiliation: Department of Metallurgical Engineering and Materials Science, IIT Bombay, Powai, Mumbai, 400076, India.
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Jangid
authors.affiliation: IITB-Monash Research Academy, IIT Bombay, Powai, Mumbai, 400076, India.|Department of Metallurgical Engineering and Materials Science, IIT Bombay, Powai, Mumbai, 400076, India.
authors.forename: D
authors.initials: D
authors.lastname: Bahadur
authors.affiliation: IITB-Monash Research Academy, IIT Bombay, Powai, Mumbai, 400076, India.|Department of Materials Engineering, Monash University, Clayton, VIC-3800, Australia.
authors.forename: N V
authors.initials: NV
authors.lastname: Medhekar
authors.affiliation: IITB-Monash Research Academy, IIT Bombay, Powai, Mumbai, 400076, India.|Department of Physics, IIT Bombay, Powai, Mumbai, 400076, India.|National Centre for photovoltaic Research and Education, IIT Bombay, Powai, Mumbai, 400076, India.
authors.forename: M
authors.initials: M
authors.lastname: Aslam