Microstructural, electrical, and optical properties of SnO2 nanocrystalline thin films grown on InP (100) substrates for applications as gas sensor devices

SnO2 thin films were grown on p-InP (100) substrates by using radio-frequency magnetron sputtering at low temperature. Transmission electron microscopy (TEM) and electron diffraction pattern measurements showed that these SnO2 thin films were nanocrystalline. The capacitance-voltage measurements at room temperature showed that the type and the carrier concentration of the nominally undoped SnO2 film were n type and approximately 1.62x10(16) cm(-3), respectively. Raman scattering measurements showed that the grain sizes of the nanocrystalline films were below 10 nm, which was in reasonable agreement with the result obtained from the high-resolution TEM measurements. Photoluminescence measurements showed a broad peak below the band-to-band emission. These results can help improve the understanding of SnO2 nanocrystalline films grown on p-InP (100) substrates for applications in high-sensitivity gas sensors. (C) 2000 American Institute of Physics. [S0021-8979(00)00118-3].