A Strategy for Improving the Interfacial Crystallinity and Carrier Mobility of SnO2 Porous Nanosolids

TL;DR

This paper presents a new calcination strategy in high-pressure oxygen to enhance interfacial crystallinity and carrier mobility in SnO2 porous nanosolids, with potential applications in oxide semiconductor devices.

Contribution

It introduces a novel calcination process that significantly improves interfacial crystallinity and carrier mobility in SnO2 PNS, supported by a simple explanatory model.

Findings

Carrier mobility reached 35 cm²/Vs after treatment.

Oxygen vacancy annihilation occurs mainly at interfaces.

Interfacial crystallinity is improved through high-pressure oxygen calcination.

Abstract

SnO2 porous nanosolid (PNS) was prepared by a solvothermal hot-press method, and a new strategy was developed to improve its interfacial crystallinity and carrier mobility. It was found that the carrier mobility of SnO2 PNS was improved after being calcined at 500 {\deg}C in high-pressure oxygen. Furthermore, the mobility was greatly increased by calcining SnO2 PNS at 350 {\deg}C for 12 h in high-pressure oxygen, and the highest mobility reached 35 cm2/Vs. On the other hand, the complex impedance spectra of the samples revealed that the annihilation of oxygen vacancies mainly happens within the interfacial region among SnO2 nanoparticles during the calcinations process in high-pressure oxygen. As a result, the interfacial crystallinity was improved and carrier mobility was increased. Based on the analysis of experimental data, a simple model was proposed to explain the above phenomena. And the simple model may find applications in improving the carrier mobility of other oxide semiconductors used in photovoltaic cells.