Effect of temperature on the current transfer mechanism in the reverse I–V characteristics of the <i>n</i>-CdS/<i>i</i>-CdS<sub><i>x</i></sub>Te1−x/<i>p</i>-CdTe heterostructure
Abstract
In this work, we study the influence of the temperature on the mechanism of current transfer in the reverse branch of the current–voltage (I–V) characteristics of n-CdS/p-CdTe heterostructures. The study of the heterostructure, using the technique of on energy-dispersive X-ray analysis, showed that a layer of CdS x Te[Formula: see text] is formed at the boundary of the heterojunction with a varying composition, being equal [Formula: see text] from the side of CdS and [Formula: see text] from the CdTe side. In the studied range of the temperatures and bias voltage, the current-voltage characteristics are described well by a power law [Formula: see text], where the exponent [Formula: see text] changes with the temperature and voltage. Under the influence of the temperature and charge carrier concentration, the mechanism of current transfer in the structure changes from exclusion ([Formula: see text]) to ohmic ([Formula: see text]), and then goes to injection ([Formula: see text]). The inhomogeneous intermediate CdS x Te[Formula: see text] i-layer at the boundary of the n-CdS/p-CdTe heterostructure is characterized by the presence of metastable states that rearrange at high temperatures and certain charge carrier concentrations. As a result of this, the exclusion slows down and electrons are injected from the rear molybdenum contact.