Hybrid PEDOT:PSS/SiC heterojunction UV photodetector with superior self-powered responsivity over A/W level

Abstract

In this Letter, an ultraviolet photodetector constructed on a simple vertical PEDOT:PSS/SiC hybrid heterojunction with superior self-powered performance was reported. Benefitting from the abundant charge carrier concentration in 4H-SiC substrate and the large built-in field at PEDOT:PSS/SiC heterointerface, the SiC based photodetector (PD) realized self-powered responsivity over A/W level, even comparable with many reported 4H-SiC avalanche photodiodes. Upon illumination with deep-UV wavelength at 254 nm, the responsivity, detectivity, and external quantum efficiency of the fabricated PD reached up to 2.15 A/W, 1.9 × 1013 Jones, and 1053%, respectively. Furthermore, the rise/decay time was as fast as 58.6/41.5 ms, the on–off switching ratio was as large as 8.73 × 103, the spectral rejection ratio (R254/R390) was as high as 4.3 × 103, and the lifetime reliability was over 195 days. Serving as a sensing pixel, the designed heterojunction PD demonstrated excellent imaging capability in homemade UV imaging system, showing promising applications in future energy-conservation photoelectronic system.

2 in. Bulk β-Ga2O3 Single Crystals Grown by EFG Method with High Wafer-Scale Quality

“…23,28 These Raman peaks can be assigned to B g (1), B g (2), A g (2), A g (3), A g (4), A g (5), A g (6), A g (7), A g (8), A g (9), and A g (10) modes, as labeled in Figure 2d. The low-frequency phonon modes [B g (1), B g (2), A g (2), A g (3)] are related to the liberation and translation of Ga I O 4 chains, the midfrequency phonon modes [A g (4), A g (5), A g (6), A g (7)] are caused by the deformation of Ga I O 4 and Ga II O 6 , and the high-frequency phonon modes are ascribed to the stretching and bending of Ga I O 4 . 23,28,29 The wafer surface quality is characterized by nine-point 3D AFM morphologies, as exhibited in Figure 3a.…”

“…As a new emerging ultrawide band gap semiconductor, gallium oxide (Ga 2 O 3 ) possesses a large band gap of 4.9 eV, a high breakdown field of 8 MV/cm, and a desirable Baliga’s figure of merit of 3214. Additionally, it exhibits strong bonding structures with Ga- and O-displacement energies of 25 and 28 eV, respectively. , These excellent material characteristics enable Ga 2 O 3 to find extensive applications in electronic and optoelectronic devices, even comparable with GaN and SiC. , In recent years, numerous successful device demonstrations of Ga 2 O 3 , such as deep-ultraviolet photodetectors, − resistive random access memories, , gas sensors, light-emitting diodes, photocatalysts, Schottky diodes, heterojunction diodes, and metal oxide semiconductor field effect transistors for power devices, − have been explored and investigated experimentally. In all examples, the performance of these devices is highly dependent on the material merit of Ga 2 O 3 .…”

“… 1 , 2 These excellent material characteristics enable Ga 2 O 3 to find extensive applications in electronic and optoelectronic devices, even comparable with GaN and SiC. 3 , 4 In recent years, numerous successful device demonstrations of Ga 2 O 3 , such as deep-ultraviolet photodetectors, 5 − 7 resistive random access memories, 8 , 9 gas sensors, 10 light-emitting diodes, 11 photocatalysts, 12 Schottky diodes, heterojunction diodes, and metal oxide semiconductor field effect transistors for power devices, 13 − 15 have been explored and investigated experimentally. In all examples, the performance of these devices is highly dependent on the material merit of Ga 2 O 3 .…”

Hafnia-based oxide enhanced Ga2O3-based photodetectors via band engineering with ultralarge responsivity

“…5–10 Ga 2 O 3 in particular offers an appropriate direct bandgap of ∼4.9 eV, high breakdown electrical field of ∼8 MV cm −1 , high absorption coefficient, and thermal stability among other advantageous properties, which make it an ideal DUV PD candidate. 11–16 Many research groups have been motivated to try to enhance the responsivity of the Ga 2 O 3 -based PDs, using a range of methods. Avalanche Ga 2 O 3 PDs consisting of an MgO layer inserted between β-Ga 2 O 3 thin films and Nb-doped SrTiO 3 substrates have shown a very high responsivity of 10 6 A W −1 at low light intensity.…”

Breakdown Characteristics of Ga2O3-on-SiC Metal-Oxide-Semiconductor Field-Effect Transistors

“…Meanwhile, crystal dislocations could be introduced at the interface of two materials, which results in harmful interface states [21]. However, thanks to the progress in epitaxial technology, such a non-ideal factor would be relieved [22,23]. Previous studies mainly focused on the on-state performance of the Ga 2 O 3on-SiC MOSFET by considering the lattice self-heating effects but with little concentration on breakdown characteristics [18,19,24,25].…”