Ultrabroadband, Sensitive, and Fast Photodetection with Needle-Like EuBiSe₃ Single Crystal

Abstract

Ultrabroadband photodetection has been a hot topic with the rapid development of materials science and the application requirements for communication, imaging, and sensing. Photodetectors based on bandgap-independent bolometry are promising candidates for detection of light from the ultraviolet to the terahertz range. Here we report a photothermoelectric detector made of an alloy of EuBiSe3 single crystal. The device shows room-temperature self-powered photoresponse from ultraviolet (375 nm) to terahertz (163 μm) with nearly uniform sensitivity against wavelength and fast response speed. Thanks to the large thermoelectric power (Seebeck coefficient) of EuBiSe3, the photovoltage responsivity derived from the incident (not absorbed) power reaches as high as 1.69 V/W at 405 nm without any bias voltage and exceeds 0.59 V/W even at terahertz frequencies, with noise-equivalent power below 1 nW/ , which is 1–2 orders of magnitude lower than reported photothermoelectric detectors. The response time is around 200 ms, nearly 2 orders of magnitude faster than silicon-based heterojunction ultrabroadband photodetectors and on the same order as the millimetric-scale graphene- and carbon nanotube-based bolometric photodetectors. In addition, the as-grown EuBiSe3 crystal possesses a unique needle-like shape, intrinsically facilitating integration of the detector. Our work demonstrates that improved thermoelectric materials hold great promise for room-temperature, high-performance, broadband photodetection.

A fast response, self-powered and room temperature near infrared-terahertz photodetector based on a MAPbI3/PEDOT:PSS composite

“…It is obvious that in the small bias voltage range, the I-V curves exhibit an Ohmic characteristic and the curves shift upon light illumination, which are typical PTE effect features. 13,33 The curves indicate that photocurrent increases with increasing laser power intensity in the À5 mV to 5 mV range of bias voltage. The I-V curves obtained over a wider bias voltage range from À1 V to 1 V are shown in Fig.…”

“…The results are three orders of magnitude faster than those of the previously reported PTE detectors. 3,13 The Seebeck coefficients of MAPbI 3 , PEDOT:PSS and MAPbI 3 / PEDOT:PSS under different light irradiation with 0.8 mW power are shown in Table S1 (ESI †). The carrier concentration (n), Hall mobility (m H ), and calculated conductivity (s H ) of the MAPbI 3 / PEDOT:PSS PD obtained by using a Hall test system are shown in Table S2 (ESI †).…”

“…11 PDs based on the PTE effect also called the Seebeck effect have shown potential applications in broadband detection benefiting from their simple synthesis strategies, self-powered ability, low power consumption and room temperature operation, which makes these devices good candidates for NIR-THz detection. 12,13 In recent years, many semiconductor nanomaterials have been considered as potential light-sensitive materials for PTE PDs. 10,[13][14][15] Typically, graphene-based PTE PDs have been studied widely, including single-bilayer interface junction formation, antenna array structure construction, and the preparation of reduced graphene oxide.…”

“…12,13 In recent years, many semiconductor nanomaterials have been considered as potential light-sensitive materials for PTE PDs. 10,[13][14][15] Typically, graphene-based PTE PDs have been studied widely, including single-bilayer interface junction formation, antenna array structure construction, and the preparation of reduced graphene oxide. 12,16,17 In our recent work, we have reported the PTE photoresponses of three-dimensional graphene foam (3D GF) 3 and reduced graphene oxide/CsPbrBr 3 .…”

“…Additionally, in view of the fact that previously reported PTE devices with millimetric channels have presented slow response times (41 ms), fast response PTE PDs are urgently required. 3,12,13 Therefore, it is desirable to explore novel thermal materials for PTE PDs.…”