Anti‐Stokes Photoluminescence of van der Waals Layered Semiconductor PbI2. Issue 21 (1st September 2017)

• Record Type: Journal Article
• Authors: Cong, Chunxiao; Shang, Jingzhi; Niu, Lin; Wu, Lishu; Chen, Yu; Zou, Chenji; Feng, Shun; Qiu, Zhi‐Jun; Hu, Laigui; Tian, Pengfei; Liu, Zheng; Yu, Ting; Liu, Ran
• Is Part Of: Advanced optical materials. Volume 5:Issue 21(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-09-01
• Subjects: anti‐Stokes photoluminescence -- layered semiconductors -- optical properties -- PbI2 -- van der Waals solids; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201700609
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Recently, organic–inorganic lead iodide perovskite has become one of the most promising emergent materials, which exhibits great potential in photovoltaics, lasing, laser cooling, etc. The building block of such great material is PbI2, a van der Waals (vdW) layered semiconductor material, which arouses increased interest also owing to its potential applications for X‐ray and γ‐ray detection, lasing, etc. Similar and even superior to some vdW layered materials such as thin layers of transition metal dichalcogenides like MoS2, WS2, MoSe2, or WSe2, PbI2 layers possess a direct bandgap of visible frequency with a wide range of thicknesses (>3 layers). This study reports the anti‐Stokes photoluminescence (ASPL) of PbI2 layers, which is very rarely investigated at present. Universe and robust ASPL in both 4H‐ and 2H‐PbI2 layers are observed and a phonon‐assisted and multiphoton absorption up‐conversion mechanisms are proposed through in situ temperature‐dependent, incident laser‐power‐dependent measurements of both Stokes photoluminescence and ASPL. The successful observation and explanation of the universal anti‐Stokes emission of PbI2 layers, will certainly enrich fundamental understandings of vdW layered semiconductors and perovskite, then further benefit to developing applications based on such emerging materials. Abstract : Anti‐Stokes photoluminescence (ASPL) of van der Waals layered semiconductor PbI2 with 4H and 2H polytypes is studied in both mechanical exfoliated and chemical‐vapor‐deposited samples. A phonon‐assisted and multiphoton up‐conversion mechanisms for the ASPL peaks in PbI2 are proposed. This work enriches fundamental understandings of PbI2 layers and synthesized perovskite based on it, and benefits to their developing applications.