Feather-Shaped InGaN Nanorods for Selective ppb-Level Detection of NO₂ Gas at Room Temperature

Abstract

Materials with peculiar nanostructures enclosing the surface play a pivotal role in a variety of applications, especially gas-sensing applications, due to their high surface-to-volume ratio. In this study, we tailored the nanorod (NR) morphology of InGaN into various unusual shapes such as bud, mace, and feather shapes and investigated the gas-sensing abilities of these structures. Remarkably, tuning the NR morphology significantly enhanced the NO2 gas response, with the feather-shaped morphology showing the best performance. The feather-shaped InGaN NRs displayed a response of 72.64% to 100 ppm NO2 gas, which is not only four times that of pristine InGaN NRs but also the highest response so far compared to that among state-of-the-art InGaN- or GaN-based NO2 gas sensors. Furthermore, photon-assisted sensing stimulated the responses of feather-shaped InGaN NRs, with the limit of detection extending to 200 ppb (6.12%). In addition, feather-shaped InGaN NRs were more selective to NO2 gas than to other target gases such as H2S, H2, NH3, and CO. The growth mechanisms of the different morphologies, as well as their enhanced NO2 gas responses, were successfully demonstrated. This morphology engineering strategy can be extended to design III-nitrides of different shapes for excellent gas-sensing applications.

Low-Temperature As-Doped In2O3 Nanowires for Room Temperature NO2 Gas Sensing

“…More defects and active sites and more surface chemisorbed oxygen species are very beneficial to the gas adsorption and reaction. Table S1 shows that the O V and O C components occupy 22.41% in full oxygen species, boosting the room temperature NO 2 gas sensing of the In 2 O 3 NWs. − …”

Photovoltaic Photodetectors Based on In2O3/InN Core–Shell Nanorods

“…Figure a,b shows the semilog plot of I – V characteristics for InN and In 2 O 3 /InN core–shell NRs in the temperature range of 200–360 K with an interval of 20 K. It is displayed that the current density values increase with an increase in temperature, and the values of In 2 O 3 /InN core–shell NRs are found to be 5.10 × 10 –5 A/cm 2 for 200 K and 5.53 × 10 –4 A/cm 2 for 360 K, whereas the current values for pristine InN NRs are 2.1 × 10 –3 and 9.1 × 10 –3 A/cm 2 for 200 and 360 K, respectively, at −1 V. The interface between the InN and In 2 O 3 core–shell NR heterostructures can be studied using diode parameters such as the barrier height (BH) and ideality factor (η). The diode parameters can be calculated using the following equations …”

Recent progress on group III nitride nanostructure-based gas sensors

“…8, which is four-times higher than that of the pristine InGaN nanorods for InGaN- or GaN-based NO 2 gas sensors. 84 The dynamic NO 2 gas response of the InGaN NRs of various shapes is depicted in Fig. 8(c–f).…”