Time-dependent oxygen vacancy distribution and gas sensing characteristics of tin oxide gas sensitive thin films

Abstract The model of gradient distributed oxygen vacancies is extensionally investigated. Based on the dynamics of oxygen vacancies under diffusion and exclusion effects in cooling process, the steady state and non-steady state solutions of the diffusion equation of the vacancies are solved. The transient distribution of oxygen vacancies is revealed during the idealized cooling process. It is concluded that the exclusion effect dominates the density distribution of oxygen vacancies throughout the crystallite. The time-dependent expressions of potential barrier [qV(x,t)], film resistance (R) and response to reducing gases (S) are formulated on the basis of Schottky model and Poisson's equation. The simulated gas sensing characteristics are in good correlation with experimental results. The constants and variables are estimated according to the correlation. Presumptions and reservations of the present expressions are also discussed.

[1]  Kengo Shimanoe,et al.  Roles of Shape and Size of Component Crystals in Semiconductor Gas Sensors I. Response to Oxygen , 2008 .

[2]  Marco Stefancich,et al.  Model for Schottky barrier and surface states in nanostructured n-type semiconductors , 2002 .

[3]  Yoshitaka Okada,et al.  Improvement of crystal quality of GaInNAs films grown by atomic hydrogen-assisted RF-MBE , 2005 .

[4]  P. Maddalena,et al.  Gas sensitive light emission properties of tin oxide and zinc oxide nanobelts , 2006 .

[5]  Kengo Shimanoe,et al.  Theory of power laws for semiconductor gas sensors , 2008 .

[6]  Kirsten E. Kramer,et al.  Detection and classification of gaseous sulfur compounds by solid electrolyte cyclic voltammetry of cermet sensor array. , 2007, Analytica chimica acta.

[7]  Chao-Nan Xu,et al.  Grain size effects on gas sensitivity of porous SnO2-based elements , 1991 .

[8]  Miao Zhang,et al.  Defect distribution and evolution in He+ implanted Si studied by variable-energy positron beam , 1998 .

[9]  Kengo Shimanoe,et al.  Roles of Shape and Size of Component Crystals in Semiconductor Gas Sensors , 2008 .

[10]  L. A. Patil,et al.  Heterocontact type CuO-modified SnO2 sensor for the detection of a ppm level H2S gas at room temperature , 2006 .

[11]  Norio Miura,et al.  Gas sensing properties of tin oxide thin films fabricated from hydrothermally treated nanoparticles: Dependence of CO and H2 response on film thickness , 2001 .

[12]  Amine Bermak,et al.  A monolithic integrated 4 × 4 tin oxide gas sensor array with on-chip multiplexing and differential readout circuits , 2007 .

[13]  He Xiuli,et al.  Thin film sensors of SnO2-CuO-SnO2 sandwich structure to H2S , 2001 .

[14]  Jacek Rynkowski,et al.  Sensors Based on SNO2 As a Detector for CO Oxidation in Air , 2001 .

[15]  Kengo Shimanoe,et al.  Receptor function of small semiconductor crystals with clean and electron-traps dispersed surfaces , 2009 .

[16]  Nicolae Barsan,et al.  Influence of annealing temperature on the CO sensing mechanism for tin dioxide based sensors–Operando studies , 2007 .

[17]  Jinsoo Park,et al.  Synthesis and high gas sensitivity of tin oxide nanotubes , 2008 .

[18]  Kengo Shimanoe,et al.  Theory of gas-diffusion controlled sensitivity for thin film semiconductor gas sensor , 2001 .

[19]  Kengo Shimanoe,et al.  New perspectives of gas sensor technology , 2009 .

[20]  Giorgio Sberveglieri,et al.  Stable and highly sensitive gas sensors based on semiconducting oxide nanobelts , 2002 .

[21]  Joachim Goschnick,et al.  A gradient microarray electronic nose based on percolating SnO(2) nanowire sensing elements. , 2007, Nano letters.

[22]  S. Morrison.  Selectivity in semiconductor gas sensors , 1987 .

[23]  Miriam Susana Castro,et al.  Influence of frozen distributions of oxygen vacancies on tin oxide conductance , 1999 .

[24]  S. Sze.  Semiconductor Devices: Physics and Technology , 1985 .

[25]  Yan Wang,et al.  Low-temperature CO gas sensors based on Au/SnO2 thick film , 2007 .

[26]  Dongxiang Zhou,et al.  Influences of cooling rate on gas sensitive tin oxide thin films and a model of gradient distributed oxygen vacancies in SnO2 crystallites , 2010 .

[27]  Dongxiang Zhou,et al.  Gas sensing characteristics of SnO2 thin films and analyses of sensor response by the gas diffusion theory , 2009 .

[28]  Ghenadii Korotcenkov,et al.  Influence of surface Pd doping on gas sensing characteristics of SnO2 thin films deposited by spray pirolysis , 2003 .

[29]  He Xiuli,et al.  Thin film sensors of SnO 2 -CuO-SnO 2 sandwich structure to H 2 S , 2001 .

[30]  Sanjay Mathur,et al.  Equivalence between thermal and room temperature UV light-modulated responses of gas sensors based on individual SnO2 nanowires , 2009 .

[31]  Kurt D. Benkstein,et al.  The potential for and challenges of detecting chemical hazards with temperature-programmed microsensors , 2007 .

[32]  Shuichi Kagawa,et al.  Study on a Detector for Gaseous Components Using Semiconductive Thin Films. , 1966 .

[33]  Noboru Yamazoe,et al.  Interactions of tin oxide surface with O2, H2O AND H2 , 1979 .

[34]  Pietro Siciliano,et al.  Air quality monitoring by means of sol–gel integrated tin oxide thin films , 1999 .

[35]  T. Seiyama,et al.  A New Detector for Gaseous Components Using Semiconductive Thin Films. , 1962 .

[36]  Dongxiang Zhou,et al.  The sensor response of tin oxide thin films to different gas concentration and the modification of the gas diffusion theory , 2009 .