Room-Temperature (RT) Extended Short-Wave Infrared (e-SWIR) Avalanche Photodiode (APD) with a 2.6 µm Cutoff Wavelength

oleh: Michael Benker, Guiru Gu, Alexander Z. Senckowski, Boyang Xiang, Charles H. Dwyer, Robert J. Adams, Yuanchang Xie, Ramaswamy Nagarajan, Yifei Li, Xuejun Lu

Format: Article
Diterbitkan: MDPI AG 2024-07-01

Deskripsi

Highly sensitive infrared photodetectors are needed in numerous sensing and imaging applications. In this paper, we report on extended short-wave infrared (e-SWIR) avalanche photodiodes (APDs) capable of operating at room temperature (RT). To extend the detection wavelength, the e-SWIR APD utilizes a higher indium (In) composition, specifically In<sub>0.3</sub>Ga<sub>0.7</sub>As<sub>0.25</sub>Sb<sub>0.75</sub>/GaSb heterostructures. The detection cut-off wavelength is successfully extended to 2.6 µm at RT, as verified by the Fourier Transform Infrared Spectrometer (FTIR) detection spectrum measurement at RT. The In<sub>0.3</sub>Ga<sub>0.7</sub>As<sub>0.25</sub>Sb<sub>0.75</sub>/GaSb heterostructures are lattice-matched to GaSb substrates, ensuring high material quality. The noise current at RT is analyzed and found to be the shot noise-limited at RT. The e-SWIR APD achieves a high multiplication gain of <inline-formula><math display="inline"><semantics><mrow><mi>M</mi><mo>~</mo><mn>190</mn></mrow></semantics></math></inline-formula> at a low bias of <inline-formula><math display="inline"><semantics><mrow><msub><mrow><mi>V</mi></mrow><mrow><mi>b</mi><mi>i</mi><mi>a</mi><mi>s</mi></mrow></msub><mo>=</mo><mo>−</mo><mtext> </mtext><mn>2.5</mn><mtext> </mtext><mi mathvariant="normal">V</mi></mrow></semantics></math></inline-formula> under illumination of a distributed feedback laser (DFB) with an emission wavelength of 2.3 µm. A high photoresponsivity of <inline-formula><math display="inline"><semantics><mrow><mi mathvariant="fraktur">R</mi><mo>></mo><mn>140</mn><mtext> </mtext><mi mathvariant="normal">A</mi><mo>/</mo><mi mathvariant="normal">W</mi></mrow></semantics></math></inline-formula> is also achieved at the low bias of <inline-formula><math display="inline"><semantics><mrow><msub><mrow><mi>V</mi></mrow><mrow><mi>b</mi><mi>i</mi><mi>a</mi><mi>s</mi></mrow></msub><mo>=</mo><mo>−</mo><mn>2.5</mn><mtext> </mtext><mi mathvariant="normal">V</mi></mrow></semantics></math></inline-formula>. This type of highly sensitive e-SWIR APD, with a high internal gain capable of RT operation, provides enabling technology for e-SWIR sensing and imaging while significantly reducing size, weight, and power consumption (SWaP).