Self-Powered p-NiO/n-Ga₂O₃ Heterojunction Solar-Blind Photodetector With Record Detectivity and Open Circuit Voltage

Abstract

Self-powered solar-blind photodetector (SBPD) promises potential applications that urgently need portability and low-power consumption. Herein, an ultrasensitive self-powered p-n heterojunction SBPD based on amorphous NiO and single crystal Ga 2 O 3 has been reliably achieved. The device exhibits a high phototo-dark-current ratio of 3 × 10 6 , ultrahigh responsivity (R) of 5 A/W, and specific detectivity of 1.6 × 10 14 Jones under 254 nm illumination at 0 V, with a solar-blind/visible rejection ratio (R 254 nm /R 460 nm ) of 2 × 10 4 . Notably, the open circuit voltage can reach 1.3 V and the response speed is significantly less than 1 ms. The comprehensive performance of the device exceeds most reported stateof-the-art Ga 2 O 3 self-powered SBPDs, which is mainly attributed to amorphous NiO/crystalline Ga 2 O 3 vertical junction structure with low-defect interface and strong built-in electric field. This work provides novel design strategies for the future development of high-performance self-powered photodetector.

Ultrasensitive Self-Powered Flexible Crystalline β-Ga2O3-Based Photodetector Obtained through Lattice Symmetry and Band Alignment Engineering

“…Based on these, we confirm that NiO can serve as the target material for constructing high-performance self-powered β-Ga 2 O 3 -based PDs. It is worth noting that although the construction of Ga 2 O 3 /NiO p–n photodetectors has been investigated, until now, the transferred flexible NiO/Ga 2 O 3 photodetectors have not been reported. , …”

“…From the results, we know that not only the high-performance flexible self-powered β-Ga 2 O 3 -based photodetector was obtained but it also provides a guideline for designing other flexible semiconductor electronic devices. 25,26 A flexible β-Ga 2 O 3 /NiO heterostructure membrane was achieved through a freestanding method, where the β-Ga 2 O 3 / NiO/LSMO/STO (111) heterostructure was covered on the mechanical supporting layer of polyethylene terephthalate (PET) and then immersed into KI solution. After a few hours, the LSMO sacrificial layer was completely dissolved; then, the flexible β-Ga 2 O 3 /NiO membrane attached onto PET can be obtained, which can be transferred to other certain substrates or directly used to prepare devices (Figure 2a).…”

Reservoir Computing Based on Oxygen-Vacancy-Mediated X-ray Optical Synaptic Device for Medical CT Bone Diagnosis

“…As a result, building X-ray synaptic devices becomes a big challenge . Ga 2 O 3 , as a wide-bandgap semiconductor material, is nontoxic, irradiation-resistant, and temperature-resistant, which gives it a natural advantage in the preparation of X-ray detectors. − Moreover, the great X-ray photoelectric intrinsic gain and the persistent photoconductivity effect caused by oxygen vacancies (i.e., deep level traps) in Ga 2 O 3 make it the material of choice for the preparation of X-ray optical synaptic devices. − …”

Enhancing Performance of GaN/Ga2O3 P‐N Junction Uvc Photodetectors via Interdigitated Structure

“…The photogenerated electronhole pairs can be automatically separated by the built-in electric field, [26][27][28][29][30] rendering self-powered photovoltaic sensing with promising applications in communication and space detection. [31][32][33] Consequently, 𝛽-Ga 2 O 3 -based PN UVC PDs have been widely studied in recent years. For instance, in 2018, Guo et al combined p-type GaN with n-type Sn-doped 𝛽-Ga 2 O 3 to fabricate a self-powered ultraviolet photodetector.…”