Bhaskar Prashant, Achtstein Alexander W, Vermeulen Martien J W, Siebbeles Laurens D A
Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands.
J Phys Chem C Nanomater Interfaces. 2019 Jan 10;123(1):841-847. doi: 10.1021/acs.jpcc.8b09665. Epub 2018 Dec 12.
Trigonal tellurium is a small band gap elemental semiconductor consisting of van der Waals bound one-dimensional helical chains of tellurium atoms. We study the temperature dependence of the charge carrier mobility and recombination pathways in bulk tellurium. Electrons and holes are generated by irradiation of the sample with 3 MeV electrons and detected by time-resolved microwave conductivity measurements. A theoretical model is used to explain the experimental observations for different charge densities and temperatures. Our analysis reveals a high room temperature mobility of 190 ± 20 cm V s. The mobility is thermally deactivated, suggesting a band-like transport mechanism. According to our analysis, the charges predominantly recombine via radiative recombination with a radiative yield close to 98%, even at room temperature. The remaining charges recombine by either trap-assisted (Shockley-Read-Hall) recombination or undergo trapping to deep traps. The high mobility, near-unity radiative yield, and possibility of large-scale production of atomic wires by liquid exfoliation make Te of high potential for next-generation nanoelectronic and optoelectronic applications, including far-infrared detectors and lasers.
三角碲是一种小带隙元素半导体，由范德华键合的碲原子一维螺旋链组成。我们研究了块状碲中载流子迁移率和复合途径的温度依赖性。通过用3 MeV电子辐照样品产生电子和空穴，并通过时间分辨微波电导率测量进行检测。使用理论模型来解释不同电荷密度和温度下的实验观察结果。我们的分析表明，室温迁移率高达190±20 cm² V⁻¹ s⁻¹。迁移率随温度降低，表明是带状传输机制。根据我们的分析，即使在室温下，电荷主要通过辐射复合进行复合，辐射产率接近98%。其余电荷通过陷阱辅助（肖克利-里德-霍尔）复合或陷入深陷阱进行复合。高迁移率、接近单位的辐射产率以及通过液体剥离大规模生产原子线的可能性，使得碲在下一代纳米电子和光电子应用中具有很高的潜力，包括远红外探测器和激光器。
