Enhancing the Performance of Aqueous Solution-Processed Cu2ZnSn(S,Se)4 Photovoltaic Materials by Mn2+ Substitution

Abstract

In this work, the Cu2MnxZn1−xSn(S,Se)4 (0 ≤ x ≤ 1) (CMZTSSe) alloy films were fabricated by a sol-gel method. Meanwhile, the effects of Mn substitution on the structural, morphological, electrical, optical, and device performance were studied systematically. The clear phase transformation from Cu2ZnSn(S,Se)4 (CZTSSe) with kesterite structure to Cu2MnSn(S,Se)4 (CMTSSe) with stannite structure was observed as x = 0.4. The scanning electron microscope (SEM) results show that the Mn can facilitate the grain growth of CMZTSSe alloy films. Since the x was 0.1, the uniform, compact, and smooth film was obtained. The results show that the band gap of the CMZTSSe film with a kesterite structure was incessantly increased in a scope of 1.024–1.054 eV with the increase of x from 0 to 0.3, and the band gap of the CMZTSSe film with stannite structure was incessantly decreased in a scope of 1.047–1.013 eV with the increase of x from 0.4 to 1. Meanwhile, compared to the power conversion efficiency (PCE) of pure CZTSSe device, the PCE of CMZTSSe (x = 0.1) device is improved from 3.61% to 4.90%, and about a maximum enhanced the open-circuit voltage (VOC) of 30 mV is achieved. The improvement is concerned with the enhancement of the grain size and decrease of the Cu instead of Zn (CuZn) anti-site defects. Therefore, it is believed that the adjunction of a small amount of Mn may be an appropriate approach to improve the PCE of CZTSSe solar cells.

Strengthening the Properties of Earth-Abundant Cu2ZnSn(S,Se)4 Photovoltaic Materials via Cation Incorporation with Ni

“…In addition, we found that the content of Sn decreased with the increase in x value in Table . In the process of selenization, the loss of Sn is inevitable, leading to the decrease of the Sn content, which has been reported in the literature . The decrease of the Zn and Sn content results in the increase of Cu/(Zn + Ni + Sn) ratio and the decrease of (Ni + Zn)/Sn ratio.…”

“…In the process of selenization, the loss of Sn is inevitable, leading to the decrease of the Sn content, which has been reported in the literature. 37 The decrease of the Zn and Sn content results in the increase of Cu/(Zn + Ni + Sn) ratio and the decrease of (Ni + Zn)/Sn ratio. It is well known that the energy required to form Cu Zn antiposition defects in the CZTSSe lattice is very low.…”

Insight into the Effect of Selenization Temperature for Highly Efficient Ni-Doped Cu2ZnSn(S,Se)4 Solar Cells

“…Therefore, the Eg of CNZTSSe will be closer to the small Eg of CZTSe as the Se content rises. Moreover, according to the first principal calculation, when Se replaces S, the orbital interaction between the valence band (VBM) top and the conduction band (CBM) bottom is weakened, thus reducing Eg (i.e., CBM = VBM + Eg) [ 47 ].…”

Energy Band Alignment by Solution-Processed Aluminum Doping Strategy toward Record Efficiency in Pulsed Laser-Deposited Kesterite Thin-Film Solar Cell

“…An efficient charge separation process at the PN heterojunction is very imperative for the effective operation of solar cells. The recombination at the PN heterojunction due to interface defects and poor band alignment is unfavorable for efficient solar cells. , The optimization of PN heterojunctions is the focal point of kesterite CZTS research. The performance of solar cells can be improved via heterojunction engineering, cation doping, interfacial engineering, and passivation layer. − The Cd-free Al 2 O 3 passivating layer and band-gap-controlled (Zn,Sn)O buffer layer enable CZTS and CZTSSe optoelectronic conversion gadgets with greater than 10% efficiency, displaying a captivating industrial value.…”

“…The recombination at the PN heterojunction due to interface defects and poor band alignment is unfavorable for efficient solar cells. 7,8 The optimization of PN heterojunctions is the focal point of kesterite CZTS research. The performance of solar cells can be improved via heterojunction engineering, cation doping, interfacial engineering, and passivation layer.…”