No abstract

Hybrid heterojunction solar cells (HHSCs) using crystalline Si nanowires (SiNWs) as the absorber and conducting polymer poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS) as the hole-selective transport layer (HTL) show great potential in both low-cost and high-power conversion efficiency (PCE). However, due to the poor wettability of the PEDOT:PSS solution on SiNWs, conformal coverage of PEDOT:PSS on SiNWs is not easy to achieve. Here, an effective method was developed to decrease the surface tension of the PEDOT:PSS and increase the wettability between PEDOT:PSS and SiNWs by incorporating organosilane into the PEDOT:PSS solution. Two kinds of organosilanes including tetramethoxysilane (TMOS) and vinyltrimethoxysilane (VTMO) were selected as the additives. The surface passivation quality of the SiNWs was dramatically enhanced. The HHSCs utilizing VTMO as the additive show a higher open circuit voltage and higher PCE compared with the TMOS adding ones. By spin-coating Ag nanowires onto the PEDOT:PSS HTL layer and using spin-coated phenyl-C61-butyric acid methyl ester as the electron-selective transport layer, a champion PCE up to 18.12% and a fill factor of 80.1% have been achieved on the full solution processed PEDOT:PSS/n-type SiNWs HHSCs. The findings provide a simple and promising method to achieve high-performance PEDOT:PSS/SiNWs HHSCs.

Hybrid heterojunction solar cells (HHSCs) using c‐Si nanowires (SiNWs) as the absorber and poly(3,4‐ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) as the hole selective transport layer (HTL) have been drawing more and more attention due to low cost process as well as high power conversion efficiencies (PCE). However, strong hygroscopicity of the PEDOT:PSS film causes serious degradation of the HHSCs. To improve the stability of the HHSCs, a kind of silane impregnating agent, isobutyltriethoxysilane (IBTEO), was selected as the additive to be added in the PEDOT:PSS solution. The hydrophobicity of the PEDOT:PSS film is much improved by formation of the hydrophobic silicone. The contact area between PEDOT:PSS and SiNWs is dramatically enlarged and more stable Si‐O‐Si bonds were formed at the PEDOT:PSS/SiNWs interface. As a result, the performance and stability of the HHSCs have been significantly improved. A PCE of 18.2% and a FF of 80.5% were obtained for a champion full solution processed PEDOT:PSS/SiNWs HHSC with 1 vol% IBTEO addition. The PCE remains 78% of the initial value after exposed 300 h in the air for the sample with IBTEO added in the PEDOT:PSS solution, while only 7% left for the control device without IBTEO addition.

Silicon-based photodetectors are important optoelectronic devices in many fields. Many investigations have been conducted to improve the performance of silicon-based photodetectors, such as spectral responsivity and sensitivity in the ultraviolet band. In this study, we combine the surface structure engineering of silicon with wide-bandgap semiconductor SnO2 films to realize textured Si-based heterojunction photodetectors. The obtained SnO2/T-Si photodetectors exhibit high responsivity ranging from ultraviolet to near-infrared light. Under a bias voltage of 1 V, SnO2/T-Si photodetectors (PDs) with an inverted pyramid texture show the best performance, and the typical responsivities to ultraviolet, visible, and near-infrared light are 0.512, 0.538, 1.88 (800 nm, 67.7 μW/cm2) A/W@1 V, respectively. The photodetectors exhibit short rise and decay times of 18.07 and 29.16 ms, respectively. Our results demonstrate that SnO2/T-Si can serve as a high-performance broadband photodetector.