Effects of excess Te on the optical and electrical properties of Cd1−xMgxTe single crystals grown by the modified vertical Bridgman method. Issue 9 (15th February 2023)

• Record Type: Journal Article
• Authors: Gao, Pandeng; Yu, Pengfei; Yang, Guizhi; Han, Zhao; Xiao, Sanxiong; Rao, Tianjing; Fu, Haijia; Luan, Lijun
• Is Part Of: CrystEngComm. Volume 25:Issue 9(2023)
• Page Start: 1446
• Page End: 1452
• Publication Date: 2023-02-15
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/d2ce01591a
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : Diagram of crystal growth process for Cd0.95 Mg0.05 Te ingots. Three large Cd0.95 Mg0.05 Te ingots with diameter of 30 mm and length of more than 100 mm are successfully grown by the modified vertical Bridgman method under different excess Te conditions. Abstract : A Cd1− x Mg x Te crystal is considered an ideal room temperature radiation detector material due to its excellent opto-electrical properties. In this paper, three large Cd0.95 Mg0.05 Te ingots with a diameter of 30 mm and a length of more than 100 mm were successfully grown by the modified vertical Bridgman method under different excess Te conditions (0.5 at%, 1.0 at% and 1.5 at%). The results showed that the as-grown Cd1− x Mg x Te crystals have cubic zinc-blende structures. The band gap of the crystals ranged from 1.43 eV to 1.52 eV, the density of Te inclusions ranged from 2.7 × 10 3 cm −2 to 1.0 × 10 5 cm −2, the resistivity ranged from 8.22 × 10 6 Ω cm to 1.51 × 10 10 Ω cm, and the IR transmittance ranged from 33% to 60%. With the increase of excess Te, the band gap, crystal resistivity and infrared (IR) transmittance decreased, and the density of Te inclusions increased. The analysis of the low temperature photoluminescence (PL) and Raman scattering spectra indicated that the crystal quality deteriorated gradually with the increase of excess Te. The crystal grown under 0.5 at% excess Te conditions had the best optical and electrical properties.