Controlled vapor phase growth of single crystalline, two-dimensional GaSe crystals with high photoresponse.
Controlled vapor phase growth of single crystalline, two-dimensional GaSe crystals with high photoresponse.
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DOI：
10.1038/srep05497
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发表时间：
2014-06-30
影响因子：
4.6
通讯作者：
Xiao K
中科院分区：
文献类型：
--
作者：
Li X;Lin MW;Puretzky AA;Idrobo JC;Ma C;Chi M;Yoon M;Rouleau CM;Kravchenko II;Geohegan DB;Xiao K
与块状晶体相比，原子级薄的二维（2D）晶体表现出新的物理特性，并具有实现下一代电子和光电子器件的潜力。然而，控制合成大型均匀单层和多层二维晶体仍然具有挑战性。在这里，我们报道了用气相沉积法在SiO2/Si衬底上控制合成二维GaSe晶体。首次获得了均匀的、大的（横向尺寸可达~60 μm）、单晶的三角形单层GaSe晶体，并对其结构和取向进行了从原子尺度到微米尺度的表征。结果表明，生长时间、生长区域、生长温度、氩气载气流速等因素可控制二维GaSe晶体的尺寸、密度、形状、厚度和均匀性。电子结构和拉曼光谱的理论建模表明，二维GaSe晶体存在直接到间接的带隙跃迁和递进的束缚诱导带隙位移。二维GaSe晶体具有p型半导体特性和高光响应性（白光照射下约1.7 A/W），可与剥离的GaSe纳米片相媲美。这些二维GaSe晶体对于下一代电子和光电子器件（如光电探测器和场效应晶体管）具有潜在的用途。
Compared with their bulk counterparts, atomically thin two-dimensional (2D) crystals exhibit new physical properties, and have the potential to enable next-generation electronic and optoelectronic devices. However, controlled synthesis of large uniform monolayer and multi-layer 2D crystals is still challenging. Here, we report the controlled synthesis of 2D GaSe crystals on SiO2/Si substrates using a vapor phase deposition method. For the first time, uniform, large (up to ~60 μm in lateral size), single-crystalline, triangular monolayer GaSe crystals were obtained and their structure and orientation were characterized from atomic scale to micrometer scale. The size, density, shape, thickness, and uniformity of the 2D GaSe crystals were shown to be controllable by growth duration, growth region, growth temperature, and argon carrier gas flow rate. The theoretical modeling of the electronic structure and Raman spectroscopy demonstrate a direct-to-indirect bandgap transition and progressive confinement-induced bandgap shifts for 2D GaSe crystals. The 2D GaSe crystals show p-type semiconductor characteristics and high photoresponsivity (~1.7 A/W under white light illumination) comparable to exfoliated GaSe nanosheets. These 2D GaSe crystals are potentially useful for next-generation electronic and optoelectronic devices such as photodetectors and field-effect transistors.
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影响因子：
38.3
作者：
Jones, Aaron M.;Yu, Hongyi;Xu, Xiaodong
通讯作者：
Xu, Xiaodong
影响因子：
2.6
作者：
LETOULLEC, R;BALKANSKI, M;KUHN, A
通讯作者：
KUHN, A
影响因子：
3.7
作者：
AUGELLI, V;MANFREDOTTI, C;VASANELLI, L
通讯作者：
VASANELLI, L
影响因子：
41.2
作者：
Geim, A. K.;Novoselov, K. S.
通讯作者：
Novoselov, K. S.
影响因子：
3.7
作者：
CAPOZZI, V;MONTAGNA, M
通讯作者：
MONTAGNA, M