Observation of photobleaching in Ge-deficient Ge16.8Se83.2 chalcogenide thin film with prolonged irradiation

Sen Zhang; Yimin Chen; Rongping Wang; Xiang Shen; Shixun Dai

doi:10.1038/s41598-017-14796-w

Observation of photobleaching in Ge-deficient Ge_16.8Se_83.2 chalcogenide thin film with prolonged irradiation

Sci Rep. 2017 Nov 6;7(1):14585. doi: 10.1038/s41598-017-14796-w.

Authors

Sen Zhang^{1

2}, Yimin Chen^{1

2

3}, Rongping Wang^{4

5

6}, Xiang Shen^{7

8}, Shixun Dai^{1

2}

Affiliations

¹ Laboratory of Infrared Materials and Devices, Ningbo University, Ningbo, Zhejiang, 315211, China.
² Key Laboratory of Photoelectric Detection Materials and Devices of Zhejiang Province, Ningbo, 315211, China.
³ University of Chinese Academy of Sciences, Beijing, 100049, China.
⁴ Laboratory of Infrared Materials and Devices, Ningbo University, Ningbo, Zhejiang, 315211, China. wangrongping@nbu.edu.cn.
⁵ Key Laboratory of Photoelectric Detection Materials and Devices of Zhejiang Province, Ningbo, 315211, China. wangrongping@nbu.edu.cn.
⁶ Laser Physics Centre, The Australian National University, Acton, Canberra, ACT 2605, Australia. wangrongping@nbu.edu.cn.
⁷ Laboratory of Infrared Materials and Devices, Ningbo University, Ningbo, Zhejiang, 315211, China. shenxiang@nbu.edu.cn.
⁸ Key Laboratory of Photoelectric Detection Materials and Devices of Zhejiang Province, Ningbo, 315211, China. shenxiang@nbu.edu.cn.

Abstract

We presented the unusual result of photobleaching (PB) in Ge-deficient Ge_16.8Se_83.2 thin films with continuous irradiation with 560 nm laser for 12000 s, which is contradicted with the previous reports that the PB only occurs in Ge_xSe_100-x films with x > 30. Observation of the dynamics variations of the photo-induced effects indicated that, photodarkening (PD) appears almost instantaneously upon light irradiation, saturates faster in a shorter time scale, and then photobleaching (PB) becomes dominant. Moreover, both PD and PB process accelerates with increasing irradiation power density. Raman spectra provided the evidence on the change of the photostructure of the samples, e.g. the structural transformation from Ge(Se_1/2)₄ edge-sharing (ES) to corner-sharing (CS) tetrahedral and homopolar Ge-Ge and Se-Se bonds to heteropolar Ge-Se bonds.

Publication types

Research Support, Non-U.S. Gov't