Title :
a-Si1-xCx:H-based transistor performance and the relationship to electrical and optical properties
Author :
Catalano, Anthony ; Newton, James ; Trafford, Mark ; Rothwarf, Allen
Author_Institution :
Solarex Thin Film Div., Newtown, PA, USA
fDate :
12/1/1989 12:00:00 AM
Abstract :
The results of measurements of (1) n- and p-channel a-Si1-x Cx inverted gate field effect transistors, (2) the photoconductivity of those alloys, and (3) the optical absorption spectra, including subband gap absorption, are discussed. Measurements of the transistor characteristics clearly show a monotonic falloff in electronic mobility with carbon addition and a somewhat slower increase in threshold voltage. The electron mobility, in the range of 0.5 cm2/V-s for a-Si:H, is still at usable levels (>0.1 cm2/V-s) even at 40% carbon concentration (gas phase). Optical absorption measurements (photothermal deflection spectroscopy) indicate that the slope of the optical absorption edge decreases with increasing carbon concentration, suggesting an increase in the tail density of states. These data, taken together with the μτ product, can be explained entirely by the decrease in mobility. The drop in the effective mobility is believed to be due to the effective widening of the band-tail state distribution
Keywords :
amorphous semiconductors; carrier lifetime; carrier mobility; hydrogen; insulated gate field effect transistors; photoconductivity; photothermal spectroscopy; silicon compounds; thin film transistors; Si1-xCx:H inverted gate field effect transistor; amorphous semiconductors; band-tail state distribution; carrier lifetime; density of states; electronic mobility; mobility lifetime product; n-channel transistor; optical absorption spectra; p-channel transistor; photoconductivity; photothermal deflection spectroscopy; plasma enhanced CVD coating; subband gap absorption; thin film transistor; Absorption; Electron mobility; Electron optics; Germanium alloys; Optical films; Photonic band gap; Photovoltaic cells; Tail; Temperature measurement; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
