Thickness effects on optical and photoelectric properties of PbSeTeO quaternary thin films prepared by magnetron sputtering
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PbSeTeO quaternary thin films with different thickness were grown on Si(100) substrates by magnetron sputtering. The as-prepared thin films show face centered cubic crystal structure and the main diffraction peak varied from PbSe(220) to PbSe(200) with the film thickness due to the transition between the surface energy and the strain energy contributions to the growth mechanism. A red shift of the absorption edge from 2200 cm−1 (4.55 μm) to 1400 cm−1 (7.14 μm) with the film thickness was obtained, indicating that increasing the thickness is an effective method to expand the absorption range of the sputtered PbSeTeO quaternary thin films. The photoelectric sensitivity increased almost linearly with the film thickness. This is attributed to the decrease of the density of states (DOS) near the top of the valence band, the increase of DOS near the conduction band bottom and the narrowing of the optical band gap calculated by the generalized gradient approximation with the Perdew–Burke–Ernzerhof exchange correlation functional formalism.
KeywordsPbSe TeO2 SeO2 Physical Property Measurement System Photoelectric Property
This work was supported by the National Nature Science Foundation of China (51271022), the Fok Ying Tung Education Foundation (132001) and the Fundamental Research Funds for the Central Universities (FRF-TP-14-008A2). Alex Volinsky acknowledges support from the National Science Foundation under the IRES 1358088 Grant.
- 15.F. Zhao, S. Mukherjee, J. Ma, D. Li, S.L. Elizondo, Z. Shi, Influence of oxygen passivation on optical properties of PbSe thin films. Appl. Phys. Lett. 92, 1–3 (2008)Google Scholar
- 35.A.D.R. Pillai, K. Zhang, K. Bollenbach, D. Nminibapiel, W. Cao, H. Baumgart, V.S.K. Chakravadhanula, C. Kübel, V. Kochergin, ALD growth of PbTe and PbSe superlattices for thermoelectric applications. ECS Trans. 10, 131–139 (2013)Google Scholar