High current fast switching n-ZnO/p-Si diode

Abstract

The authors report on the high current density n-ZnO/p-Si heterojunction diode that has been fabricated by atomic layer deposition (ALD) of 70 nm thin ZnO on a p-Si substrate. While the diode was formed at four different ALD temperatures of 80, 100, 150 and 200 °C, the 100 °C processed diode showed an optimal behaviour of an on–off ratio over 3.3 × 103 and a high forward current density, ∼300 A cm−2 at 3 V. Although the highest film conductance appeared from the 200 °C deposited ZnO layer, nanometre thin SiO x was also revealed at the ZnO/p-Si interface; it might cause a high reverse leakage current level. Our high current density diode also demonstrates a fast switching performance without any reverse recovery delay, which is often observed at a usual Si p–n diode.

The influence of Y contribution on crystallographic, topographic and optical properties of ZnO: A heterojunction diode application

“…The rectification ratio (RR) of Al/ZnO:Y/p-Si heterojunction diodes was calculated from the ratio of forward and reverse current at 3 V. The RR value of Al/YZO-5/p-Si heterojunction diode is found as 3 Â 10 4 at +3.0 V. This rectification ratio is higher than the values in the earlier studies (Table 2) [49][50][51][52][53][54][55][56][57].…”

Preparation of ZnO film on p-Si and I-V characteristics of p-Si/n-ZnO

“…Heterojunction of n-ZnO/p-Si have potential applications in the visible and ultraviolet photodiodes, gas sensors among many others [4][5][6] . Fast switching of n-ZnO/p-Si diode without any reverse recovery delay has been reported by Choi et al 1 . Such reverse recovery delay is often observed in Si p-n diode.…”

“…It is well known that undoped ZnO films generally indicate n-type conduction. ZnO films have been epitaxially grown on sapphire or Si substrates by several physical and chemical methods such as molecular beam epitaxy (MBE), sputtering, atomic layer deposition, metal oxide chemical vapor deposition (MOCVD) and sol-gel [1][2][3][4][5] . Silicon is suitable for the integration of optoelectronic devices.…”

Memory Select Devices

“…Oxide p-n heterojunction was also demonstrated in pZnORh 2 O 3 /n-InGaZnO 4 and achieved on/off ratio of 10 3 (at ±5 V), ideality factor of ∼2.3, and threshold voltage of 2.1 V [29]. Si substrates can be used as a part of heterojunction diodes as demonstrated in n-ZnO/p-Si [30] and n-Ge-nanowire/p-Si [31]. The ON current of oxide-based heterojunction diodes is often limited by both contact resistance and density of states of the oxide materials.…”