A promising two-dimensional solar cell donor: Black arsenic–phosphorus monolayer with 1.54 eV direct bandgap and mobility exceeding 14, 000 cm2 V−1 s−1. (October 2016)

• Record Type: Journal Article
• Authors: Xie, Meiqiu; Zhang, Shengli; Cai, Bo; Huang, Yong; Zou, Yousheng; Guo, Bin; Gu, Yu; Zeng, Haibo
• Is Part Of: Nano energy. Volume 28(2016:Oct.)
• Page Start: 433
• Page End: 439
• Publication Date: 2016-10
• Subjects: Excitonic solar cells -- Power conversion efficiency -- Black arsenic–phosphorus monolayer -- First-principle calculations -- Type-II semiconductor heterojunction; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2016.08.058
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Excitonic solar cells (XSCs) have attracted tremendous attentions due to their high solar-to-electric power conversion efficiency (PCE). However, to further improve the PCE of XSC, finding an efficient donor material with both suitable direct bandgap and high carrier mobility is still a great challenge. Here, we report a black arsenic–phosphorus monolayer as highly efficient donor for XSCs based on first-principle calculations. Firstly, monolayer arsenic-phosphorus polymorphs with α, β, γ, δ, and ε phases were built, among which α–AsP and β–AsP have been verified to be thermodynamically stable. Significantly, monolayer α–AsP possesses a direct bandgap with energy of 1.54 eV, which covers the main energy of solar spectrum. Moreover, its electronic mobility is as high as 14, 380 cm 2 V −1 s −1, which is much higher than silicon. These two crucial merits made it a promising candidate as donor materials for XSC device and the theoretical simulations demonstrate a maximum PCE of 22.1% for the primarily designed α–AsP/GaN XSC. Interestingly, the suitable electronic structure of α–AsP enables a formation of perfect type-II semiconductor heterojunction with GaN, which will boost the separation and transport of photogenerated carriers with the assistance of built-in field and high mobility. Particularly, α phase few-layer material of arsenic-phosphorus alloy has been experimentally synthesized recently, which paves the way for experimental realization of black arsenic–phosphorus monolayer donor. Graphical abstract: The maximum PCE of monolayer α–AsP/GaN-based excitonic solar cell (XSC) could achieve 22.1%, which is competitive with the best to date in 2D thin-film solar cells. Highlights: Monolayer α–AsP as highly efficient donor for XSCs is proposed. α–AsP has direct gap (1.54 eV) and high electron mobility (14, 380 cm 2 V −1 s −1 ). We design a α–AsP/GaN XSC with maximum PCE of 22.1%.