Ultraviolet and visible photo-response of transparent conductive Al-doped ZnO (AZO)/n-Silicon isotype heterojunction device

Abstract

In this work, the electrical and photoresponse measurements of a transparent conductive Al-doped ZnO (AZO)/n-Si heterojunction device were conducted in visible light and UV wavelengths. AZO film was deposited by sputtering onto an n-Si wafer and investigated by means of morphological, chemical and electrical characterizations. The AZO/n-Si rectifying device exhibits an excellent reproducibility without noticeable variations after 90 days of measurements. At self-powered mode, the maximum on/off ratios were determined as 3081 for visible light and 4778 for UV light illumination of 365 nm. The responsivity and detectivity of the AZO/n-Si photodetector were 0.128 A W−1 and 1.05 × 1011 Jones for 365 nm, whereas they were 0.055 A W−1 and 4.60 × 1010 Jones for 395 nm, respectively (at −2.0 V). This study demonstrated that the n-AZO/n-Si isotype heterojunction photodetector was fabricated at low cost and it is a potential candidate in both the visible region and the UV region with a good performance, in contrast to the widely studied pn heterojunctions.

Surface plasmon resonance effects of Ag@ZnO core–shell nanostructure in UV and visible light for photodiode applications

“…Although the changes at different voltages show similar behavior to each other, it is seen that the increase in photocurrent is low with increasing light intensities up to 40 mW and then increases rapidly after 40 mW. This nonlinear variation, that is, the low photocurrent at low light intensities, was attributed to the recombination of electrons and holes [59][60][61] and also to the presence of traps between the Ag@ZnO/p-Si interface. In other words, at high light intensities, recombination is thought to decrease and traps are de-trapped, thereby increasing the photocurrent.…”

“…The EQE of an optical device is the parameter that helps to analyze the efficiency of the photodetector in converting the incoming photonic signal into an electrical signal 59 . EQE‐ V plots were obtained (Figure 8D) using the parameters obtained from the I – V characteristics under UV light as a function of light intensity with the help of the following equation 63,82 : $$$$\begin{equation}{rm{EQE}} = \frac{( I_{\mathrm{light}} - I_{\mathrm{dark}})/q}{P /hv}\end{equation}$$$$where h is the Planck constant, and ν is the incident light frequency…”

“…The EQE of an optical device is the parameter that helps to analyze the efficiency of the photodetector in converting the incoming photonic signal into an electrical signal. 59 EQE-V plots were obtained (Figure 8D) using the parameters obtained from the I-V characteristics under UV light as a function of light intensity with the help of the following equation 63,82 :…”

Ultrafast and Ultrabroadband UV–vis-NIR Photosensitivity under Reverse and Self-Bias Conditions by n+-ZnO/n-Si Isotype Heterojunction with >1 kHz Bandwidth

“…Chatzigiannakis et al have recently reported only photocurrent spectra of an ALD grown ZnO/Si n-n isotype heterojunction photodetector. Similarly, a few other reports are also available, − but detailed investigation and analyses such as photocurrent transients, photosensitivity, response time, stability, low power detectability, and photoresponse under frequency-modulated illuminations have not been performed to show the ZnO/Si isotype junction as a high-performance broadband photodetector.…”