Photoluminescence mapping and time-domain thermo-photoluminescence for rapid imaging and measurement of thermal conductivity of boron arsenide
Photoluminescence mapping and time-domain thermo-photoluminescence for rapid imaging and measurement of thermal conductivity of boron arsenide
复制标题
DOI：
10.1016/j.mtphys.2020.100194
复制
发表时间：
2019-10
影响因子：
11.5
通讯作者：
Shuai Yue;G. A. Gamage;M. Mohebinia;D. Mayerich;V. Talari;Yu Deng;F. Tian;Shenyu Dai;Haoran Sun;V. Hadjiev;Wei Zhang;G. Feng;Jonathan Hu;Dong Liu;Zhiming Wang;Z. Ren;J. Bao
中科院分区：
文献类型：
--
作者：
Shuai Yue;G. A. Gamage;M. Mohebinia;D. Mayerich;V. Talari;Yu Deng;F. Tian;Shenyu Dai;Haoran Sun;V. Hadjiev;Wei Zhang;G. Feng;Jonathan Hu;Dong Liu;Zhiming Wang;Z. Ren;J. Bao
立方砷化硼(BAS)由于最近的实验证明其超高导热系数κ高于1000W/m·K而受到越来越多的关注，但它的禁带尚未得到解决，也缺乏一种简单而有效的方法来检测其晶体质量。此外，传统的κ测量方法破坏性大、耗时长，不能满足高κ材料快速筛选的迫切需求。在实验上建立了1.82EV作为κ的间接带隙，并观察到了室温带边光致发光后，我们发展了两种新的光学技术，它们可以在不需要制备样品的情况下提供快速和无损的表征：光致发光映射和时域热致发光。PL映射提供了毫米晶体表面上晶体质量和κ的近乎实时的图像；而TDTP使我们能够拾取样品表面上的任何斑点，并使用纳秒激光脉冲测量其κ。这些新技术揭示了表观单晶不仅在κ中是不均匀的，而且是由非常明显的κ结构域组成的。由于PL映射和TDTP是基于带边PL及其对温度的依赖关系，因此它们可以应用于其他半导体，从而为高κ半导体材料的快速识别和开发铺平了道路。
Cubic boron arsenide (BAs) is attracting greater attention owing to the recent experimental demonstration of ultrahigh thermal conductivityκhigher than 1000 W/m·K. However, its bandgap has not been settled and a simple yet effective method to probe its crystal quality is missing. Furthermore, traditionalκmeasurement methods are destructive and time consuming, thus they cannot meet the urgent demand for fast screening of highκmaterials. After we experimentally established 1.82 eV as the indirect bandgap of BAs and observed room-temperature band-edge photoluminescence, we developed two new optical techniques that can provide rapid and non-destructive characterization ofκwith little sample preparation: photoluminescence mapping (PL-mapping) and time-domain thermo-photoluminescence (TDTP). PL-mapping provides nearly real-time image of crystal quality andκover mm-sized crystal surfaces; while TDTP allows us to pick up any spot on the sample surface and measure itsκusing nanosecond laser pulses. These new techniques reveal that the apparent single crystals are not only non-uniform inκbut also are made of domains of very distinctκ. Because PL-mapping and TDTP are based on the band-edge PL and its dependence on temperature, they can be applied to other semiconductors, thus paving the way for rapid identification and development of high-κsemiconducting materials.