Comprehensive Review on CdTe Crystals: Growth, Properties, and Photovoltaic Application
Bibin John, S. Varadharajaperumal
Abstract
Abstract Despite the deep interest of materials scientists in cadmium telluride (CdTe) crystal growth, there is no single source to which the researchers can turn towards for comprehensive knowledge of CdTe compound semiconductor synthesis protocols, physical properties and performance. Considering this, the present review work focuses to bridge this shortcoming. The direct band gap (Eg) CdTe crystals have been in limelight in photovoltaic application (PV) since the optoelectronic properties such as Eg (1.49 eV), absorption coefficient (~105 cm–1), p-type conductivity, carrier concentration (6 × 1016 cm–3) and mobility (1040 cm2/(V s)) at the room temperature are reported that optimum for solar cells. Additionally, Cd-based compounds such as CdTe and CdZnTe have also been widely studied in the field of α and γ-ray radiation detector, because of their extraordinary advantages like large atomic number, low weight, high mechanical hardness, flexibility, and the availability of the constituent materials. CdTe has demerits like toxicity and high melting temperature, which will complicate the growth of stoichiometric cadmium telluride crystals at high temperatures. In this regard, the review work focused the periodic evolution of the growth protocols until now. The different synthesis methods, characterization, and recent progress in the field of crystalline CdTe were discussed briefly. Important optical and electrical characteristics are presented in the tables and remaining issues have discussed, this could be looked into for further research. The applications of CdTe crystals for photovoltaic fields are also discussed in this review paper.