Black-Silicon Ultraviolet Photodiodes Achieve External Quantum Efficiency above 130%

Abstract

At present ultraviolet sensors are utilized in numerous fields ranging from various spectroscopy applications via biotechnical innovations to industrial process control. Despite of this, the performance of current UV sensors is surprisingly poor. Here, we break the theoretical Shockley-Queisser limit and demonstrate a device with a certified external quantum efficiency (EQE) above 130% in UV range without external amplification. The record high performance is obtained using a nanostructured silicon photodiode with self-induced junction. We show that the high efficiency is based on effective utilization of multiple carrier generation by impact ionization taking place in the nanostructures. While the results can readily have a significant impact on the UV-sensor industry, the underlying technological concept can be applied to other semiconductor materials, thereby extending above unity response to longer wavelengths.

Unveiling the faint ultraviolet Universe

“…A study to develop a CMOS detector with readout noise below 0.15 e − is currently in progress with results from the simulation of the silicon circuit showing single-photon sensitivity [131]. Another promising technological development is in black silicon nano-structures with self induced junctions, allowing effective QE above 100% without external amplification in the UV wavelength range [51]. A combination of these technologies would lead to a powerful new detector optimized for low-noise UV observations.…”

Silicon avalanche photodiode with photon detection efficiency superior to 0.65 electrons/photon in the wavelength range of 114 to 170 nm

“…We could not find any data on the ultraviolet quanta absorption depth for boron silicides in the referenced literature. shows the spectral dependences of Ɛ for non-avalanche silicon photodiodes, made using black-silicon (b-Si) technology 15 and well-known, non-avalanche AXUV photodiodes. 16 The data for b-Si and AXUV photodiodes were taken from Ref.…”

“…5. As one can see from the referenced literature, the active region of b-Si photodiodes is covered with a 20-nm thick Al 2 O 3 layer 15 and the AXUV active region is covered with a 4-to 8-nm thick nitrided SiO 2 layer. 16 Figure 5(b) also demonstrates the spectral dependences of the ultraviolet quanta absorption depth for SiO 2 3 and for Al 2 O 3 .…”

Observation of Si 2p Core‐Level Shift in Si/High‐κ Dielectric Interfaces Containing a Negative Charge

“…However, it is also utilized and developed to passivate silicon solar cells and other state‐of‐the‐art photonic devices in which the internal electric field is used to repel charge carriers deeper into Si bulk away from surface defects. [ 9–11 ] Several explanations, for example, crystal defects, broken bonds, and local charge distributions, have been presented to explain the static charge formation and field‐effect passivation. The origin of the charge has been related to the Si/dielectric interface rather than the top oxide‐gate metal interface.…”