Enhanced Performance of Gallium‐Based Wide Bandgap Oxide Semiconductor Heterojunction Photodetector for Solar‐Blind Optical Communication via Oxygen Vacancy Electrical Activity Modulation

Abstract

Gallium oxide (β‐Ga2O3) is a prominent representative of the new generation of wide‐bandgap semiconductors, boasting a bandgap of ≈4.9 eV. However, the growth process of β‐Ga2O3 materials introduces unavoidable oxygen vacancies (Vo), leading to persistent photoconductivity (PPC), a phenomenon that severely hinders device performance. In this study, an innovative approach is successfully developed by introducing high p‐orbital energy nitrogen (N). This leads to the formation of a hybridized state with O 2p orbitals in β‐Ga2O3, resulting in the creation of GaON and suppressing the electrical activity of Vo. Through meticulous experimentation and advanced computational methods, a comprehensive and insightful explanation of the regulation and mechanism underlying this passivation process is offered. Moreover, pn‐junction solar‐blind photodetectors are engineered using hybridized GaON thin films with p‐type CuPc. These photodetectors demonstrate exceptional characteristics, including ultra‐low dark current (10−14 A), high photo‐to‐dark current ratio (106), and rapid decay speed (0.008 s) even at zero bias. Based on these advancements, a solar‐blind ultraviolet communication system is designed, featuring straightforward and reliable encoding, easy implementation, and robust anti‐interference capabilities.

Carbon quantum dots capped with metal ions for efficient optoelectronic applications

“…Similar C–C/CC, C–O/C–N and CO bonds in the high-resolution C 1s spectra were observed for the In–C-dots, Ga–C-dots, and Sr–C-dots 32,33 (Fig. S4a, c and e, ESI†).…”

“…6d shows the designed pattern, printed pattern observed during daylight, and the fluorescence effect at 395 nm and 365 nm. 32 We designed a code with two different concentrations of inks made by single emission Mn–C-dots and double emission Al–C-dots. Based on different wavelengths of excitation, the anti-counterfeiting code could display different patterns.…”

High-Detectivity and Broadband Photodetector Based on LiInP2Se6 Semiconductors

“…In the inset of Figure b,c, the top two bands near the conduction band represent donor defect levels, while the lower band near the valence band represents the acceptor defect level. As the photon energy at the wavelength range of 600–700 nm is less than the E g (2.06 eV) of LiInP 2 Se 6 , the positive TA signals can be attributed to the photo-induced transition process from acceptor to donor defects (inset in Figure b), which is known as the excited state absorption (ESA) process. − The delay dynamics of ESA signals is shown in Figure b. The existence of ESA indicates the presence of defects in the crystal.…”

Straddling SnSe2/SnS2 van der Waals tunneling heterostructures for high performance broadband photodetectors

“…8–14 Moreover, they provide the advantage of designing heterostructures without the requirement of precise atomic lattice matching, resulting in greater freedom in designing and engineering electronic and optoelectronic devices. 15–22 The use of vdW heterostructures composed of 2D crystals as tunneling transistors is a highly promising field for low-power applications. 23,24 These heterostructures allow for the manipulation of carrier densities and electron affinities, enabling the tailored design of band alignments.…”