Amorphous silicon based nipiin structure for color detection

Abstract

Hydrogenated amorphous silicon based nipiin three color detectors with a bias voltage controlled spectral response have been fabricated. These band-gap and mobility-lifetime product engineered structures employed as two terminal devices exhibit a dynamic range above 95 dB. The maximum of the spectral response shifts by variation of the applied voltage. Three linearly independent spectral response curves can be extracted to generate a red-green-blue signal. Conventional spatial color separation with optical filters is transferred into a voltage multiplexed read out sequence. Bias voltage switching under different monochromatic illumination and illumination switching-on transients for different bias voltages are carried out to investigate the time dependent behavior of the photocurrent. Based on these results optimization criteria to accelerate the transient behavior and to determine the maximum frame rate for color detection are presented.

Color Sensors and Their Applications

“…In a first version, the sensor had the nip layers made of a-SiC:H with E G ¼ 2 eV, the first i layer after the p region and the last n region were also a-SiC:H but with E G ¼ 1.9 eV, and the last i region was a-SiGe:H with E G ¼ 1.55 eV and had a gradual composition change with linearly varying E G at both ends [133][134][135][136]. This sensor may have constituted the starting point for subsequent improvements, and such a modified version was probably employed in successful imaging arrays of 512 Â 512 pixels with a pixel pitch of 100 Â 100 mm [137][138][139].…”

Characterization of nanocrystalline silicon carbide films

“…Due to its fine tunable electrical and optical properties by plasma parameters, hydrogenated amorphous silicon carbide films have attracted a great interest and have been used in many kinds of optoelectronic devices, such as solar cell windows layer, color sensors, and thin film light emitting and detecting devices [1][2][3][4][5]. Crystalline SiC compared to its amorphous counterpart has been considered to be a promising semiconductor material to operate at high temperature, high power, high frequency, and high radiation environment due to its good electrical and mechanical characteristics such as electron mobility (1000 cm 2 /V s), electron saturation velocity (2.0-2.7 · 10 7 cm/s), break electronic field (2-3 · 10 6 V/cm), high melting point and high thermal conductivity [6].…”

Two-color amorphous silicon image sensor

“…[7][8][9][10][11][12] Their working principle is that shorter wavelength ͑blue/green͒ radiation is strongly absorbed and generates photocarriers in a shallower region of the semiconductor, while longer wavelength ͑red͒ illumination creates electron-hole pairs more uniformly throughout the whole thickness of the active layer. Most color sensors are either multijunction structures that are biased to collect photocarriers at a desired depth, or single p-i-n devices with a nonuniform intrinsic layer to achieve a desired electric field profile.…”