Large area image sensing structures based on a-SiC:H: a dynamic characterization

Abstract

Abstract:In recent works large area hydrogenated amorphous silicon p-i-n structures with low conductivity doped layers were proposed as single element image sensors. The working principle of this type of sensor is based on the modulation, by the local illumination conditions, of the photocurrent generated by a light beam scanning the active area of the device. In order to evaluate the sensor capabilities is necessary to perform a response time characterization. This work focuses on the transient response of such sensor and on the influence of the carbon contents of the doped layers. In order to evaluate the response time a set of devices with different percentage of carbon incorporation in the doped layers is analyzed by measuring the scanner-induced photocurrent under different bias conditions. (C)

Electrical performance in iron-passivated porous silicon film

“…Many efforts have been focused to produce light emitting devices (LEDs), PS Schottky diodes, gas sensors and solar cells using this material [6][7][8][9][10][11]. For example, Badawy [11] has reported that the solar cells based on porous silicon and covered by an oxide film, are stable against environmental attacks.…”

Optical signal and image processing device optimized for optical readout

“…The increased responsivity of the switching diode under green bias illumination can be ascribed to a self bias process. The illuminated sensing diode, acting as a load, converts the light bias into a spatially varying electric field across the switching one [6]. This leads to a reverse self biasing of the bottom diode that switches to its OFF state becoming sensitive to the incoming scanner light.…”

“…In sensor #1 a 90 nm thermally evaporated Cr light-screening interlayer, composed of 290 · 290 lm 2 pixels with 40 lm spacing, was included. This layer prevents most (90%) of the light impinging on the switching diode from reaching the sensing one [6]. In sensor #2 the interconnection between the top and bottom junction is performed by the 50 · 50 lm 2 Cr floating contact via an a-SiN insulator layer.…”

Optically addressed read–write device based on tandem heterostructure

“…In sensor #2 a 90 nm thermally evaporated Cr light-screening inter-layer, composed by 290 · 290 lm 2 pixels with 40 lm spacing, was included. This layer prevents most (90%) of the light impinging on one diode from reaching the other one [7].…”