Metastable Antimony‐Doped SnO₂ Quantum Wires for Ultrasensitive Gas Sensors

Abstract

Doping is fundamental to controlling the properties of bulk semiconductors. Although the antimony (SbV)‐doping strategy is widely employed in the design of practical tin oxide (SnO2) semiconductor gas sensors for higher signal‐to‐noise ratio, challenges remain to dope semiconductor nanocrystals since the diffusion of impurity atoms may be far from realized at the synthesis temperatures used. Herein, a metastable Sb‐doping strategy is proposed to overcome the serious receptor‐versus‐transducer mismatch in SnO2 quantum wires (QWs). The solvothermal synthesis of colloidal SbIII‐doped SnO2 QWs has been conducted at 180 °C, whereby the antimony amount is varied to optimize the structural and morphological properties for higher surface activity and electrical conductivity. A unique n‐type doping mechanism arising from the stable presence of SbIII on SnO2 (101) facets via SnII‐O‐SbIII is demonstrated. Further, the use of sensitive (down to 4 ppb, the lowest detection limit ever reported), fast (response and recovery time of 43 s and 96 s toward 10 ppm of H2S) gas sensors for H2S detection at near room temperature (40 °C) is showcased. The metastable Sb‐doping strategy may pave the way to ultrasensitive gas sensor possessing low power consumption and excellent integration compatibility to satisfy the increasing demand for ubiquitous and reliable gas detection.

Solution-processed metal doping of sub-3 nm SnO2 quantum wires for enhanced H2S sensing at low temperature

“…Apparently, the transition metal doping affects the formation of SnO 2 QWs and shortens the length of the resultant QWs. 35 Density functional theory (DFT) calculations were carried out to figure out the formation mechanism of the M-doped SnO 2 QWs and the results are presented in Fig. 1e–h.…”

Room-Temperature Semiconductor Gas Sensors: Challenges and Opportunities

“…(c) Response of Sb-doped SnO 2 QWs sensors to 10 ppm of H 2 S at different temperatures. (Reproduced with permission from ref . Copyright [2022], Wiley-VCH GmbH.)…”

“…To realize RT gas sensors with high SNR, novel strategies and methods are being explored to overcome the receptorversus-transducer mismatch. The metastable Sb-doping strategy 191 proposed for SnO 2 QWs yielded a distinctive n-type doping mechanism due to the stable presence of Sb III on the SnO 2 (101) facets via Sn II -O-Sb III (Figure 2a,b). To improve the receptor and transducer functions, the structural and morphological properties of SnO 2 QWs were engineered by varying the antimony amount.…”

Temperature‐Modulated Selective Detection of Part‐per‐Trillion NO2 Using Platinum Nanocluster Sensitized 3D Metal Oxide Nanotube Arrays

“…[8][9][10][11] However, NO 2 always exists under the presence of other interfering gases, such as formaldehyde (FA), toluene, acetone, and SO 2 , and the sensitive and selective detection trace amount of NO 2 among the interfering gases remains a bottleneck challenge. Chemiresistive gas sensors made of metal-oxide semiconductors, such as tin oxide (SnO 2 ) [12][13][14] and zinc oxide (ZnO), [15][16][17][18] possess a number of highly attractive merits, including small formfactor and being integratable with other semiconductor devices, long life-time, and low cost. Thus, they are playing the critical roles in a smart and sustainable city for safety and healthy monitoring.…”