A 4H-SiC UV Phototransistor with Excellent Optical Gain Based on Controlled Potential Barrier

Di Benedetto L, Licciardo GD, Erlbacher T, Bauer AJ, Rubino A (2020)

Publication Type: Journal article

Publication year: 2020

Journal

IEEE Transactions on Electron Devices Institute of Electrical and Electronics Engineers (IEEE)

Book Volume: 67

Pages Range: 154-159

Article Number: 8913626

Journal Issue: 1

DOI: 10.1109/TED.2019.2950986

Abstract

In this article, we report the experimental results of a visible-light-blind 4H-polytype silicon carbide phototransistor able to detect ultraviolet (UV) radiations for wavelengths lower than 380 nm with a significative improvement in the optical gain compared with the state-of-the-art of 4H-SiC UV phototransistors. From the electro-optical measurements, the device shows a dark current of 0.62 pA, an ON-/OFF-current ratio of seven orders of magnitude up to bias voltage of -0.5 V, and an excellent optical gain of 1.14·10⁵ at 300 nm, whereas it is only 2.6·10^-3 at 400 nm demonstrating a good rejection of visible radiations. Besides having high optical gain, the phototransistor is also more sensitive than the conventional 4H-SiC UV detectors for wavelengths with low penetration depths, because its structure is designed to have the electric field up to the radiated surface where the photogenerated electron-hole pairs are efficiently swept up before recombination occurs. The operating principle of the detector is also investigated, and we experimentally proved that differently from the conventional 4H-SiC bipolar junction transistor phototransistor, it is based on the change in the potential barrier height, which controls the current flow, due to the variation in the Fermi levels when the electron-hole pairs are photogenerated. A comparison with the state-of-the-art of 4H-SiC UV phototransistors is reported.

Authors with CRIS profile

Tobias Erlbacher Lehrstuhl für Elektronische Bauelemente

Involved external institutions

Università degli Studi di Salerno

Italy (IT) Fraunhofer-Institut für Integrierte Systeme und Bauelementetechnologie (IISB)

Germany (DE)

How to cite

APA:

Di Benedetto, L., Licciardo, G.D., Erlbacher, T., Bauer, A.J., & Rubino, A. (2020). A 4H-SiC UV Phototransistor with Excellent Optical Gain Based on Controlled Potential Barrier. IEEE Transactions on Electron Devices, 67(1), 154-159. https://dx.doi.org/10.1109/TED.2019.2950986

MLA:

Di Benedetto, L., et al. "A 4H-SiC UV Phototransistor with Excellent Optical Gain Based on Controlled Potential Barrier." IEEE Transactions on Electron Devices 67.1 (2020): 154-159.

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