Jinqian Zhang,Jun Liu,Yue Tian,Jiawen Guo,Wenjie Kong,Lizhen Long
Two-dimensional (2D) materials have emerged as promising candidates for photodetection applications, due to their unique structural and optical properties. Herein, we conducted a comprehensive investigation of the 2D Te-based photodetector. The crystal structure, angle-resolved polarized Raman (ARPR) spectroscopy, and theoretical analysis demonstrate the in-plane lattice anisotropy of Te, underlining its suitability for polarization-dependent photodetection. Photocurrent measurements over a broad spectral range (from 365 to 1310 nm) reveal excellent photoresponse characteristics, with responsivity ( R λ ) and detectivity ( D* ) values reaching up to 1189 A/W and 11.51 × 10 8 Jones, respectively, under 1064 nm illumination. Furthermore, the Te-based photodetector exhibits superior stability, retaining approximately 90 % of its initial performance after six months of ambient exposure. Polarization-sensitive photodetection experiments show significant dichroism ratios (up to 4.6 for 1064 nm illumination), emphasizing the potential of 2D Te for advanced polarization applications. The combination of the broad spectral response, high anisotropy ratio, and long-term stability positions 2D Te as a promising candidate for future photodetection technologies.
Chenghao Zhang,Kangpeng Jin,Hongliang Dong,Wenlong Xu,Pengfei Xu,Zhenhua Yan,Weiyun Zhao,Biao Xu,Liangwei Fu
Modulating electrical and thermal transport through zero-dimensional point defects and one-dimensional dislocations are extensively investigated. However, the systematic study of exploring single-atom-layer vacancies for improving thermoelectric (TE) performance remains rare. In this study, we modulate the number density of single-atom-layer two-dimensional (2D) Te vacancies in lead telluride (PbTe) for the first time through bismuth and indium doping. DFT calculations reveal (Bi, In) co-doping lowers the formation energy of such defects, confirming the feasibility of this method. 2D Te vacancies simultaneously enhance phonon scattering and evoke bond softening, significantly lowering the lattice thermal conductivity . Meanwhile, indium doping generates resonant level in the energy band, which increases the carrier concentration without deteriorating the Seebeck coefficient drastically. As a result, a peak TE figure of merit ( zT ) of ∼1.6 and an average zT ( zT avg ) of 1.17 are achieved in the (Bi, In) co-doped PbTe. Furthermore, a high conversion efficiency of 6.5 % is obtained for the fabricated 2-pair module at a temperature difference of 500 K.
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