Sensitivity and selectivity improvement of rf sputtered WO3 microhotplate gas sensors

Comparative microscopic and spectroscopic analysis of temperature-dependent growth of WO3 and W0.95Ti0.05O3 thin films

“…Although pure WO 3 is a recognized candidate for gasochromic, electrochromic, and photochromic devices, its morphological characteristics are strongly dependent on the conditions and methods used in its fabrication, as revealed in the literature [1][2][3][4][5][6][7][8][9][10]. An improvement in its gasochromic detection sensitivity and in its increased temperature range of operation as a sensor, which for undoped thin films of WO 3 grown by radio-frequency (RF) magnetron sputtering are achieved at a deposition temperature of *200°C [9,10], as well as in its electrochromic and photocatalytic properties, has been achieved by doping with appropriate metals or by addition of metal/metal oxide additives [7][8][9][10][11][12][13][14][15][16][17][18].…”

“…An improvement in its gasochromic detection sensitivity and in its increased temperature range of operation as a sensor, which for undoped thin films of WO 3 grown by radio-frequency (RF) magnetron sputtering are achieved at a deposition temperature of *200°C [9,10], as well as in its electrochromic and photocatalytic properties, has been achieved by doping with appropriate metals or by addition of metal/metal oxide additives [7][8][9][10][11][12][13][14][15][16][17][18]. Due to electron transfer from the metal oxide to the added metal on its surface, a decrease in the electron concentration in the metal oxide surface layer occurs.…”

Analytical Investigations of Concentration Dependences of Gas Sensors Sensitivity

“… ðàáîòàõ [8,10] ïîêàçàíî, ÷òî ïðè âçàèìî-äåéñòâèè ìîëåêóë H 2 S ïðîèñõîäèò èõ ðåàêöèÿ ñ àäñîðáèðîâàííûìè Ã×Ì àòîìàìè êèñëîðîäà è ïîñëåäóþùåé äåñîðáöèåé ïðîäóêòîâ ðåàêöèè (SO 2 è H 2 O) [10] èëè ñ îáðàçîâàíèåì ñóëüôèäîâ ìåòàëëîâ [8].…”

“…Ýòî îçíà÷àåò, ÷òî ìåõàíèçì ïîâåðõíîñ-òíûõ ðåàêöèé ìîëåêóë Í 2 S íå ñâÿçàí ñ àäñîð-áèðîâàííûìè íà ïîâåðõíîñòè Ã×Ì ãðóïïàìè OH ads , à çàâèñèò îò êîíöåíòðàöèè àäñîðáèðî-âàííîãî ïîâåðõíîñòüþ Ã×Ì êèñëîðîäà, ÷òî ïîäòâåðaeäàåòñÿ ðåçóëüòàòàìè ðàáîò [8,10].…”

Multisensor Microsystem for Measuring the Concentration of Gases Co, H2 , C3 H8 , Co2

“…Существенным недостатком такой системы является высокое энергопотребление. Еще одна технология [11] обеспечивает форми-рование на диэлектрической мембране методами объемного травления кремниевой подложки че-тырех химических сенсоров. Недостатками дан-ной мультисенсорной системы являются слож-ность в изготовлении, нестабильное воспроизве-дение параметров поликремниевого нагревателя и низкий уровень рабочих температур сенсоров [11,12].…”