Comprehensive Understanding of the Role of Emitter Layer Thickness for Metal–Oxide–Semiconductors Based Solar Cells
Kenan Özel, A. Yıldız
Abstract
Achieving low-cost and high-performance solar cells based on heterojunction of metal–oxide–semiconductors with silicon (Si) is a difficult task. We herein report the development of cost-effective and efficient SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /p-Si heterojunction-based solar cells using the low-temperature hydrothermal method. The fabrication of SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Si heterojunction-based solar cells is realized with various thicknesses of SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> layer deposited by controlling the hydrothermal deposition time. The measurements of scanning electron microscopy, optical spectra, four-point probe conductivity, current–voltage ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I–V</i> ), and capacitance–voltage ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C–V</i> ) reveal that the thickness of SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> emitter layer significantly influences the electrical properties and the photovoltaic performance of the devices. The best power conversion efficiency of 3.09% ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J<sub>sc</sub></i> = 20.28 mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V<sub>oc</sub></i> = 0.312 V, and FF = 48.84%) is achieved for the solar cell having n-SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> thickness of 391 nm. The experimental findings disclose that the efficiency of the cells is extremely dependent on the emitter layer thickness, which plays a vital role in determining light-harvesting characteristics and carrier collective capabilities of the cells.