Low-Cost Tin Oxide Transparent Conductive Films for Silicon Heterojunction Solar Cells

Abstract

Indium-based transparent conductive oxide (TCO) films are widely used in various photoelectric devices including silicon heterojunction (SHJ) solar cells. However, high cost of indium-based TCO films is not conducive to mass production of the SHJ solar cells. A variety of indium-free or indium-less TCOs are explored and utilized presently. Here, SnOx films are deposited by reactive plasma deposition (RPD) with metal tin as the evaporation source. The metal-reaction deposited SnOx films feature low resistivity (<2 × 10−3 Ω cm), high mobility (35.93 cm2 V−1 S−1), and wide optical bandgap (3.64 eV). A power conversion efficiency (PCE) of 25.33% is achieved on the champion SHJ solar cell using the metal-reaction deposited SnOx as the back TCO layer, which indicates the application potential of the metal-reaction-deposited SnOx as a low-cost substitute for In-based TCOs in SHJ solar cells and other photoelectric devices.