Giant bulk piezophotovoltaic effect in 3R-MoS2
Giant bulk piezophotovoltaic effect in 3R-MoS2
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DOI：
10.1038/s41565-022-01252-8
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发表时间：
2022-11-21
影响因子：
38.3
通讯作者：
Iwasa, Yoshihiro
中科院分区：
文献类型：
--
作者：
Dong, Yu;Yang, Ming-Min;Iwasa, Yoshihiro
鉴于其与固体中的波函数几何形状的固有耦合及其提高太阳能转换效率的潜力，体光伏效应（BPVE）在过去十年中引起了相当大的兴趣（1-14）。BPVE最初在铁电氧化物材料中被发现和开发（2），现在已经在广泛的新兴材料中被探索，例如Weyl半金属（9，10）、货车德瓦尔斯纳米材料（11，12，14）、氧化物超晶格（15）、卤化物钙钛矿（16）、有机物（17）、块状Rashba半导体（18）等。然而，缺乏一种可行的实验方法来优化光伏性能。在这里，我们表明，应变诱导极化可以显着提高BPVE在非中心对称的菱形型二硫化钼多层薄片（即，3R-MoS 2）。这种极化增强的BPVE，称为压电光伏效应，表现出独特的晶体取向依赖性，在该增强主要体现在扶手椅方向的3R-MoS 2晶格，而在Z字形方向保持基本完整。此外，当施加类似于0.2%的面内拉伸应变时，光电流增加超过两个数量级，与最先进的材料相媲美。这项工作揭示了应变工程在提高光伏性能方面的潜力，这可能会促进在应变二维层状材料及其货车德瓦尔斯异质结构中探索新的光电过程。
Given its innate coupling with wavefunction geometry in solids and its potential to boost the solar energy conversion efficiency, the bulk photovoltaic effect (BPVE) has been of considerable interest in the past decade(1-14). Initially discovered and developed in ferroelectric oxide materials(2), the BPVE has now been explored in a wide range of emerging materials, such as Weyl semimetals(9,10), van der Waals nanomaterials(11,12,14), oxide superlattices(15), halide perovskites(16), organics(17), bulk Rashba semiconductors(18) and others. However, a feasible experimental approach to optimize the photovoltaic performance is lacking. Here we show that strain-induced polarization can significantly enhance the BPVE in non-centrosymmetric rhombohedral-type MoS2 multilayer flakes (that is, 3R-MoS2). This polarization-enhanced BPVE, termed the piezophotovoltaic effect, exhibits distinctive crystallographic orientation dependence, in that the enhancement mainly manifests in the armchair direction of the 3R-MoS2 lattice while remaining largely intact in the zigzag direction. Moreover, the photocurrent increases by over two orders of magnitude when an in-plane tensile strain of similar to 0.2% is applied, rivalling that of state-of-the-art materials. This work unravels the potential of strain engineering in boosting the photovoltaic performance, which could potentially promote the exploration of novel photoelectric processes in strained two-dimensional layered materials and their van der Waals heterostructures.