Photoluminescence of two-dimensional GaTe and GaSe films. (30th July 2015)

• Record Type: Journal Article
• Authors: Pozo-Zamudio, O Del; Schwarz, S; Sich, M; Akimov, I A; Bayer, M; Schofield, R C; Chekhovich, E A; Robinson, B J; Kay, N D; Kolosov, O V; A I Dmitriev, ; Lashkarev, G V; Borisenko, D N; Kolesnikov, N N; Tartakovskii, A I
• Is Part Of: 2D materials. Volume 2:Number 3(2015)
• Publication Date: 2015-07-30
• Subjects: 2D semiconductors -- III-VI materials -- optical properties -- photoluminescence; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/2/3/035010
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: Gallium chalcogenides are promising building blocks for novel van der Waals heterostructures. We report on the low-temperature micro-photoluminescence (PL) of GaTe and GaSe films with thicknesses ranging from 200 nm to a single unit cell. In both materials, PL shows a dramatic decrease by 10 4 –10 5 when film thickness is reduced from 200 to 10 nm. Based on evidence from continuous-wave (cw) and time-resolved PL, we propose a model explaining the PL decrease as a result of non-radiative carrier escape via surface states. Our results emphasize the need for special passivation of two-dimensional films for optoelectronic applications.