Piezo‐Phototronic Effect on Selective Electron or Hole Transport through Depletion Region of Vis–NIR Broadband Photodiode

Abstract

Silicon underpins nearly all microelectronics today and will continue to do so for some decades to come. However, for silicon photonics, the indirect band gap of silicon and lack of adjustability severely limit its use in applications such as broadband photodiodes. Here, a high-performance p-Si/n-ZnO broadband photodiode working in a wide wavelength range from visible to near-infrared light with high sensitivity, fast response, and good stability is reported. The absorption of near-infrared wavelength light is significantly enhanced due to the nanostructured/textured top surface. The general performance of the broadband photodiodes can be further improved by the piezo-phototronic effect. The enhancement of responsivity can reach a maximum of 78% to 442 nm illumination, the linearity and saturation limit to 1060 nm light are also significantly increased by applying external strains. The photodiode is illuminated with different wavelength lights to selectively choose the photogenerated charge carriers (either electrons or holes) passing through the depletion region, to investigate the piezo-phototronic effect on electron or hole transport separately for the first time. This is essential for studying the basic principles in order to develop a full understanding about piezotronics and it also enables the development of the better performance of optoelectronics.

Alternating Current Photovoltaic Effect

“…The above‐illustrated phenomenon is rather universal and has also been observed for other typical types of junctions, including Schottky contact (Al/p‐Si/ITO), Ohmic contact (ITO/p‐Si/ITO), metal–insulator–semiconductor (MIS, p‐Si/AlO x /ITO), and p–insulator–n (PIN, p‐Si/AlO x /ZnO). The details of the fabrication process are described in the Experimental Section and previous work . Briefly, a 200 nm thickness of Al and 100 nm of ITO were deposited as the electrodes via electron‐beam evaporator and physical vapor deposition.…”

Advances in Piezo‐Phototronic Effect Enhanced Photocatalysis and Photoelectrocatalysis

“…Common approaches to creating piezopotential in photocatalytic and photoelectrocatalytic semiconductors include ultrasonic vibration, mechanical stirring, mechanical force, thermal expansion and some other methods, among which the former three are most widely adopted ( Figure 7 ). [ 26,34,37,46–49 ]…”

Transparent, Flexible Silicon Nanostructured Wire Networks with Seamless Junctions for High-Performance Photodetector Applications

“…8-9, [21][22][23][24] Amongst the 1D materials studied to date, Si NWs have shown the most promise due to their well-controlled electrical and optical properties along with superior photoresponse performances. 14,28,29 High photoresponse from individual crystalline Si NW connected by short porous silicon segments has also been demonestrated. 30 Photoresponse of a single Si NW based photodetector was shown to increase with decreasing wire diameter.…”