The performance of a perovskite-silicon tandem photovoltaic device coupled with the infrared-enhanced response titanium subnitride film

Abstract

Two kinds of carrier’s passivating contact capping stacks have been fostered for an asymmetric silicon based solar cell, in which ITO/a-SiOx(In) is for hole selection and possesses graded distribution of In, Si, O elements as well as intrinsic- and p-type ultrathin SiOx(In) layer trait, while the SiOx-TiNy layer on rear of n-Si absorber is for electron selection and behaves as a degenerated material with higher electron concentration (1023-1024 /cm3). By using Hall effect, X-ray photoemission and minority carrier lifetime measurements and simulation analyses with AFORS-HET software of TiNy films and ITO/a-SiOx(In)/n-Si/SiOx-TiNy device, respectively, it is found that the performance of the device is strongly correlated to the N deficiency of TiNy film, in addition the simulation results demonstrate that the reduced density of interface state (Dit(E)) and the enhanced near-infrared response (EQE) lead to an increase of open-circuit voltage from 578.6 to 744.1 mV, and power conversion efficiency (PCE) has increased by 30.65%, compared with the prototype of semiconductor-quasi-insulator-semiconductor device (SQIS). Moreover, a monolithic tandem device by n-i-p type perovskite cell tunnel-connected to the modified SQIS cell has achieved a PCE of 31.39%, which is predicted through an available estimation under the maximum values of the Jsc, Voc and pFF.