Potential Pulse ALD for Room Temperature Fabrication of Stoichiometric CdTe Nanofilms. Issue 5 (1st January 2019)

• Record Type: Journal Article
• Authors: Zhang, Xiaoyue; Shen, Sheng; Howell, Paulie; Cheng, Wei; Mubeen, Syed; Stickney, John
• Is Part Of: Journal of the Electrochemical Society. Volume 166:Issue 5(2019)
• Page Start: H3249
• Page End: H3256
• Publication Date: 2019-01-01
• Subjects: Electrodeposition -- Electrodeposition - semiconductors -- Semiconductors - II-VI -- CdTe -- nanofilms -- pulse plating; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0061905jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Deposition of thin film compound semiconductors with good control over stoichiometry, crystallinity and thickness is essential for a range of diverse applications such as solar cells, photocatalysis, thermoelectrics, photodetectors, etc. In this work, nanometer-thick cadmium telluride (CdTe) films with exceptional control over its stoichiometry were electrodeposited onto Au substrates using a novel potential pulse atomic layer deposition (PP-ALD) process. The films were electrodeposited from an acidic aqueous solution of CdSO4 and TeO2 at room temperature using a flow cell electrodeposition set-up. Deposition potential and effect of solution flow were first investigated to optimize the codeposition process. Potential pulses were then subsequently introduced to achieve atomic layer deposition of CdTe. X-ray diffraction (XRD), Scanning electron microscope (SEM), Electron probe microanalysis (EPMA), Energy Dispersive X-Ray Analyzer (EDX) were used to characterize resulting CdTe films. XRD studies of the films showed the evolution of a much sharper peak corresponding to CdTe cubic (111) than is customarily observed for CdTe thin films grown at room temperature. The optimized PP-ALD method was also used to deposit CdTe on Au nanowire-array electrodes. Initial results show high-quality CdTe deposits conformally coated on Au nanowire arrays, which could open pathways for ultrathin light absorber solar energy conversion devices.