The Influence of Oxygen on the Electrical Properties of Bulk and Thin Films of PbTe Semiconductors

Abstract

PbTe based semiconductors are characterized by a narrow energy gap and can be used for IR detectors, light emission diodes, lasers and thermoelectric devices. The objective of the present work was to study the effect of oxidation on the properties of n- and p-type PbTe samples prepared by powder metallurgy (bulk materials) and physical vapor deposition (thin films with thickness ∼1 μm). The samples were characterized by SEM, AES and XRD. The Hall effect and electrical conductivity of PbTe samples have been examined over the 80 – 300 K temperature range. The experimental results are accounted for in the framework of a model that is based on: 1- the fast diffusion of oxygen along grain boundaries (GB); 2 - oxygen absorption that generates acceptor states at GB (short time annealing) and the growth of PbTe oxides on GB with properties corresponding to wide band semiconductor (lengthy annealing); 3 - the creation of potential barriers on GB due to oxidation with a thermally activated dependence of the conductivity.

A Combined Photoelectron Spectroscopy and ab Initio Study of the Adsorbate System O2/PbTe(001) and the Oxide Layer Growth Kinetics

“…The geometry and the energy levels for the clean PbTe(001) surface were studied in detail both experimentally and theoretically. − Investigations on the adsorption of oxygen on semiconductors like PbTe are also of great importance since the oxygen has a direct impact on the performance of devices fabricated from these materials. In this context, numerous electrophysical studies of thin films, such as the Hall coefficient or conductivity measurements, showed that the surface oxidation of semiconductors results in dramatic changes of different device properties, see for example refs and . Though these studies clearly demonstrate that these properties are sensitive to the interaction of oxygen with the materials, they lack detailed surface information which is essential to understand the underlying interaction mechanism.…”

A Review of Nanocrystalline Film Thermoelectrics on Lead Chalcogenide Semiconductors: Progress and Application

“…Various methods including decomposition at solid-state synthesis [6] and preparation of nanopowders [7] are used for the preparation of nanostructured materials. In this work, the flash evaporation technology method, first developed by Prof. Z. Dashevsky for Bi 2 Te 3 based compounds [10,11], was used for the preparation of the lead chalcogenides (PbTe, PbTe, PbS) semiconductor films [12][13][14][15][16][17][18][19][20][21][22][23][24][25]. The setup for the film preparation is presented in Figure 1 [11].…”