Activation and Deactivation of Silicon Surface Passivation by Niobium Oxide Films

Abstract

Niobium oxide (Nb2O5) films can provide excellent passivation for crystalline silicon (c‐Si) surface after postdeposition annealing, however, its kinetic behavior and mechanism have not been explored. Herein, it is demonstrated that surface passivation by solution‐processed Nb2O5 films can be activated by low‐temperature annealing (<200 °C) within several minutes, with the activation energy of 0.40 and 0.57 eV for hydrofluoric acid (HF) and RCA pretreated surfaces, respectively. Moreover, passivation is deactivated by higher‐temperature annealing (>350 °C), with the deactivation energy of 0.86 and 1.06 eV for HF and RCA pretreated surfaces, respectively. The results combined with surface‐sensitive X‐Ray photoelectron spectroscopy (XPS) measurements indicate that the passivation kinetics of Nb2O5 on the surface of c‐Si are strongly related to the diffusion of hydrogen into and out of the Nb2O5/c‐Si interface.

Sn‐Doped Nb2O5Films as Effective Hole‐Selective Passivating Contacts for Crystalline Silicon Solar Cells

“…We deduce that the film quality is not affected significantly with the annealing at 350 °C, based on the remained high V OC of the device and our previous studies on the passivation kinetics. [ 35 ] The possible reason for the serious decay of device performance could be ascribed to the interfacial reaction or element diffusion (e.g., Ag), for which more studies are needed in the further work.…”

Surface Termination Tuning Photoexcited-Carrier Dynamics and Carrier Transfer Pathway on Silicon for High-Performance Photocatalytic H2 Evolution from Pure Water

“…Tuning surface termination has been proven to be an effective way to improve silicon efficiency. 21 By regulating the terminal groups on the Si surface and modifying the surface physical and chemical properties, the surface passivation can be reduced, which enhances the photocatalytic performance and stability of Si. 22 Si photocatalysts are often prepared by surface modification using hydrofluoric acid (HF) etching.…”