Study of Structural Optical and Electrical Properties of Pure and Doped Zno Thin Film

Abstract

Transparent conductive oxide (TCO) thin films have attracted much attention due to their interesting electrical and optical properties which are suitable for several optoelectronic device applications such as light-emitting diodes (LEDs), solar cells, sensors, flat panel displays, etc. Tin-doped indium oxides (ITO) have been popularly used as TCO for all the optoelectronic device applications. However, the high price of ITO due to the scarcity of Indium led researchers to seek an alternative candidate for ITO. In recent years, the abundant, inexpensive, and nontoxic zinc oxide (ZnO) has received extensive attention because of its novel properties such as direct energy wide band gap (3.37 eV), large exciton binding energy (60 meV), high thermal and chemical stability and environmental friendly applications and is considered as a promising alternative TCO material to replace ITO. In order to widen the potential Applications of ZnO thin films, dopants/ impurities are incorporated in order to induce stability and to obtain certain desired properties like wider or narrower bandgap, higher optical transmittance, favorable electrical properties etc. Impurities such as Group III elements (Al3+, Ga3+, and In3+) have utilized as the most suitable dopants, which substitute Zn2+ ions and operate as shallow n-type donors. Among these elements, Ga3+ is the most successful and efficient dopant for the better electrical conductivity of the film and chosen as a dopant in the present study. newline