Author(s): Ouyang, C (Ouyang, Chen); Li, SQ (Li, Shangqing); Ma, JL (Ma, Jinglong); Zhang, BL (Zhang, Baolong); Wu, XJ (Wu, Xiaojun); Ren, WN (Ren, Wenning); Wang, X (Wang, Xuan); Wang, D (Wang, Dan); Ma, ZZ (Ma, Zhenzhe); Wang, TZ (Wang, Tianze); Hong, TS (Hong, Tianshu); Yang, PD (Yang, Peidi); Cheng, Z (Cheng, Zhe); Zhang, Y (Zhang, Yun); Jin, KJ (Jin, Kuijuan); Li, YT (Li, Yutong)

Source: COMMUNICATIONS PHYSICS Volume: 4 Issue: 1 Article Number: 5 DOI: 10.1038/s42005-020-00508-w Published: JAN 4 2021

Abstract: Intense terahertz (THz) electromagnetic fields have been utilized to reveal a variety of extremely nonlinear optical effects in many materials through nonperturbative driving of elementary and collective excitations. However, such nonlinear photoresponses have not yet been obeserved in light-emitting diodes (LEDs), let alone employing them as fast, cost-effective, compact, and room-temperature-operating THz detectors and cameras. Here, we report ubiquitously available LEDs exhibiting photovoltaic signals of similar to 0.8V and similar to 2ns response time with signal-to-noise ratios of similar to 1300 when being illuminated by THz field strengths similar to 240kV/cm. We also demonstrated THz-LED detectors and camera prototypes. These unorthodox THz detectors exhibited high responsivities (>1kV/W) with response time four orders of magnitude shorter than those of pyroelectric detectors. The mechanism was attributed to THz-field-induced impact ionization and Schottky contact. These findings not only help deepen our understanding of strong THz field-matter interactions but also contribute to the applications of strong-field THz diagnosis. Interest in the exploration of non-perturbative nonlinear optical phenomena driven by intense terahertz fields has seen a leap forwards with the recent development in femtosecond laser-based table-top sources for strong THz radiation. The authors present intense THz-field-induced effects in ubiquitously available LEDs illuminated by strong THz pulses, paving the way to their use in detecting and imaging intense THz radiation.

Accession Number: WOS:000607114400005

ISSN: 2399-3650

Full Text: https://www.nature.com/articles/s42005-020-00508-w