Search

CuSbS2 thin films were in situ grown by reactive co-sputtering and the effects of the growth temperature on film composition, structure and morphology were investigated. It is demonstrated that orthorhombic chalcostibite CuSbS2 thin films with uniform morphology, pure phase and grain size over 2 µm can be obtained for growth temperature of 300 ℃, while higher growth temperature results in the formation of Cu3SbS4 phase and lower growth temperature leads to Sb2S3 secondary phase. The grown CuSbS2 film shows an optical absorption coefficient of higher than 104 cm−1, an optical band gap of 1.52 eV and p-type conductivity. Solar cell devices with configuration of glass/Mo/CuSbS2/CdS/i-ZnO/ITO/Ag were fabricated and yield power conversion efficiency of 0.52%. The incompatible interfaces including absorber/back contact (the absence of beneficial MoS2 interface layer) and absorber/buffer layer (unfavorable “cliff”-like conduction band offset) interfaces have been considered as the key factor limiting efficiency.

Cu 2 ZnSn(S,Se) 4 thin films were fabricated by selenization of reactively sputtered precursors. The precursors showed a fully sulfurized Cu 2 ZnSnS 4 phase with compact surface and columnar structure. The evolutions of composition, morphology and phases for the selenized films were investigated. The selenization resulted in dramatic changes in morphologies, but demonstrated excellent stability on metallic composition and negligible volume expansion of the selenized films. The selenized films show densely packed large grains and single kesterite Cu 2 ZnSn(S,Se) 4 phase. The solar cell with the structure of ITO/i-ZnO/CdS/CZTSSe/Mo/Glass presents the highest power conversion efficiency of 4.3%. The key limitation factor is due to low fill factor, which is mainly caused by a low shunt resistance and severe voltage-dependent photocurrent collection.

Comparing with traditional single organic light-emitting device (OLED), the luminance efficiency and lifetime of tandem OLED are significantly improved. Therefore, it is of crucial importance to in depth study the influence of microcavity effect on the performance of top emitting tandem OLED. In this paper, taking the blue organic light emitting device for example, the change rule of optical and electrical properties of top-emitting tandem blue-light device are studied by combining optical simulation with practical experiments. The specific experiment is as follows. The top emitting tandem blue organic light devices are fabricated, in which the two light-emitting layers are located at the first anti node and second anti node, the second anti node and third anti node, and the third anti node and fourth anti node in the optical structure of the device respectively. It is found that the performance of the device is better when the two emitting layers of the top-emitting tandem blue light device are located at the second anti node and third anti node in the optical structure of the device respectively. That is to say, when the current density of the device is 15 mA/cm2, the current efficiency of the device reaches 10.68 cd/A, color coordinate (CIEx, y) of the device is (0.14, 0.05), and the time of the brightness decreases from 100% to 95% in 1091.55 hours, which is likely to be due to the fact that when the cavity length of the device is long, it can not only improve the recombination rate of hole and electron in the first light-emitting unit, weaken the surface plasmon polarition effect, reduce the influence of the fluctuation of the film thickness on the cavity length of the device, but also play a role of wrapping partials to a certain extent, improve the efficiency and prolong the device lifetime. The research results provide an important theoretical and data basis for designing the top-emitting tandem blue light device with high efficiency and long lifetime. In the future, we will continue to systematically and detailedly study the top emitting tandem organic light-emitting devices, which will provide strong support for preparing the laminated devices with high efficiency long-lifetime, and lower cost.