Search

Element doping into the Cu 2 ZnSn(S,Se) 4 (CZTSSe) absorber is an effective method to optimize the performance of thin film solar cells. In this study, the Cu 2 In x Zn 1-x Sn(S,Se) 4 (CIZTSSe) precursor film was deposited by magnetron cosputtering technique using indium (In) and quaternary Cu 2 ZnSnS 4 (CZTS) as targets. Meanwhile, the In content was controlled using the direct current (DC) power on In target (P In). A single kesterite CIZTSSe alloy was formed by successfully doping a small number of In3+ into the main lattice of CZTSSe. The partial Zn2+ cations were substituted by In3+ ions, resulting in improving properties of CZTSSe films. Morphological analysis showed that large grain CIZTSSe films could be obtained by doping In. The well-distributed, smooth, and dense film was obtained when the P In was 30 W. The band gap of CIZTSSe could be continuously adjusted from 1.27 to 1.05 eV as P In increased from 0 to 40 W. In addition, the CIZTSSe alloy thin film at P In = 30 W exhibited the best p-type conductivity with Hall mobility of 6.87 cm2V−1s−1, which is a potential material as the absorption layer of high-performance solar cells. [ABSTRACT FROM AUTHOR]

(Na 0.1 Cu 0.9) 2 ZnSn(S,Se) 4 thin films with a single kesterite phase were synthesized using a sol-gel spin-coating method accompanied by rapid post-annealing. In this study, we investigated the effect of selenization time on the crystal quality and photoelectric performance of the (Na 0.1 Cu 0.9) 2 ZnSn(S,Se) 4 films. It was found that the crystallinity and morphology of the films was enhanced, and some of bigger Se substituted for the S site in (Na 0.1 Cu 0.9) 2 ZnSn(S,Se) 4 with increasing the selenization time. The bandgap of the film can be regulated from 1.04 eV to 0.99 eV by varying the selenization time. In addition, all films showed p-type conductive characteristics, and films with optimal electrical performance could be obtained by optimizing the selenization time. Finally, the (Na 0.1 Cu 0.9) 2 ZnSn(S,Se) 4 thin film with the best crystal quality and optical-electrical characteristics was obtained at an optimized selenization time of 15 min. A high power conversion efficiency (PCE) of 3.92% was obtained for the (Na 0.1 Cu 0.9) 2 ZnSn(S,Se) 4 device, which is 42% higher compared to that of the undoped Cu 2 ZnSn(S,Se) 4 (CZTSSe) device. [ABSTRACT FROM AUTHOR]

We have synthesized Cu 2 Mg x Zn 1–x Sn(S,Se) 4 (0 ≤ x ≤ 0.6) thin films by a facile sol-gel method, and studied the influence of Mg concentration on the crystal structure, surface morphology and photoelectric performance of Cu 2 Mg x Zn 1–x Sn(S,Se) 4 thin films systematically. It was shown that the smaller Zn 2+ in Kesterite phase Cu 2 ZnSn(S,Se) 4 will be replaced by larger Mg 2+ , forming uniform pure phase Cu 2 Mg x Zn 1–x Sn(S,Se) 4 . The band gap of Cu 2 Mg x Zn 1–x Sn(S,Se) 4 films can be adjusted from 1.12 to 0.88 eV as the x value changes from 0 to 0.6. Furthermore, the Cu 2 Mg x Zn 1–x Sn(S,Se) 4 thin films with large grain size, smooth surface and less grain boundaries was obtained at an optimized condition of x = 0.2. The carrier concentration of Cu 2 Mg x Zn 1–x Sn(S,Se) 4 thin film reaches the maximum 6.47 × 10 18 cm −3 at x = 0.2, which is a potential material to be the absorption layer of high efficiency solar cells. [ABSTRACT FROM AUTHOR]

Bandgap engineering of Cu 2 In x Zn 1−x Sn(S,Se) 4 alloy films for photovoltaic application has been investigated. Cu 2 In x Zn 1−x Sn(S,Se) 4 (0 ≤ x ≤ 0.6) alloy films with different In contents and a single kieserite phase were fabricated by using a simple low-cost sol-gel method. The influence of In content on the structure, morphology, and optical and electrical properties of Cu 2 In x Zn 1−x Sn(S,Se) 4 films was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscope (TEM), X-Ray photoelectron spectroscopy (XPS), optical absorbance, and room-temperature Hall measurements. The results of XRD, TEM, and XPS demonstrated the substitution of some Zn atoms by In in Cu 2 In x Zn 1−x Sn(S,Se) 4 films. The Hall measurements show that the carrier concentration of the Cu 2 In x Zn 1−x Sn(S,Se) 4 (0 ≤ x ≤ 0.6) decreases with increasing In content and that the p-type Cu 2 In x Zn 1−x Sn(S,Se) 4 films with preferable electrical properties can be obtained by adjusting the In content during film deposition. The optical measurements indicate that the bandgap of Cu 2 In x Zn 1−x Sn(S,Se) 4 films with kesterite structure can be continuously tuned in the range of 1.13–1.01 eV as x is increased from 0 to 0.6. Our results show that the Cu 2 In x Zn 1−x Sn(S,Se) 4 alloy is a potentially applicable material for bandgap grading absorption layers in high-power-conversion-efficiency solar cells. [ABSTRACT FROM AUTHOR]