SU758252A1 - Photoelectric converter - Google Patents

Description

The invention relates to optoelectronics and can be used in high-speed optical information processing systems, in particular in holographic storage devices.

Known photoelectric semiconductor converters on photodiodes [Ί 3 and ^ 23.

Also known photoelectric semiconductor converter, ¹

which is an integral matrix with cells having one two-emitter phototransistor. Single-type emitters of phototransistors of cells are connected by mutually perpendicular tires C3].

The disadvantage of the known transducer is a long transient process when switching weak light signals (more than 1 μs). As a result, at high frequencies, the device does not allow photosensitivity to be higher than ΙΟ * · ⁴ - 10 * ^{: 2} J / element.

Photosensitivity is influenced by interference from control signals and leakage tempo currents, which depend on temperature, doubling as it increases by 10 ° C. Thus, the disadvantages of this photoreconverter are low speed, low threshold photosensitivity and a narrow temperature range.

Modern processing systems>. optical information require a high sensitivity of the photoconverter 10 ^'14 - U ^ J at an element ^ε at 10 Hz speed in a wide temperature range (from -60 to +80 ⁱⁿ C).

The purpose of the invention is to increase the speed, the threshold photosensitivity and the expansion of the temperature range. The goal is achieved by the fact that in a photoelectric semiconductor converter containing a matrix of photosensitive cells made on a device with a pn-junction, each cell is supplemented with a second identical device having a light-proof coating and connect in parallel to the p-η-junction of the devices of the cell generator of the current, and each of the devices -'k "inputs of the differential amplifier;

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The current generator creates an optimal mode of the photovoltaic converter, thanks to its scum its speed increases by 3-4 orders. At the same time, however, the threshold sensitivity of the phototransducer / deteriorates due to the increased tempo currents. In the general case, the sensitivity is limited by interference from the control signals, tempo leakage currents through ρ-B junctions and tempo currents caused by the current generator. The use of two identical semiconductor devices in each cell with dimming one of them and connecting the outputs to a differential amplifier allows you to compensate for all of these interferences, while maintaining speed. Interference associated with temperature changes, also compensate- ·. are, because the devices of the cell are the same and are in the same condition; viyah, ’’

Figure 1 presents the electrical circuit of the proposed photovoltaic converter, ’in figure 2? design of one of the device options.

The photoelectric converter contains a matrix of photosensitive cells ί consisting of two identical photosensitive semiconductor devices, such as phototransistors 2 and 3. Light affects phototransistor 2 cells, and the phototransistor 3 is protected by a light-proof coating. The phototransistors of the cell are two-emitter, Pn-type with a common collector 4. Control signals are fed to their base 5 through a capacitance of 6 p-η-junction formed by the base and emitter 7. The emitters of 8 phototransistors of 2 cells belonging to a specific column are 'connected to one input of the differential amplifier 9, and 8 devices emitters 3 of the same cell - _h to the second input of the amplifier 9. as a current generator providing current operating mode of large-η-p junctions (hence mode small time constant) is used in each device trance A p-p-type resistor formed by Substrate 10 (emitter), an epitaxial layer of a collector 4 (base) and a base 5 of a pn-transistor (collector). The device has a generator 11

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readout pulses and two power supplies; they provide power for the operation of phototransistors and current generators.

Both phototransistors of each cell operate dynamically with charge accumulation. The control signals from the generator 11 pulses arrive at the base of 5 phototransistors through the barrier capacitances of 6 emitter junctions 7. They provide charging of the barrier capacitances of 6 phototransistors, which in the pause between control pulses are discharged by the photocurrent, the tempo Fock leakage and the current generator. Obviously, the noise signals, the tempo currents, 'which are the same for the adjacent phototransmitters of the integrated circuit, are compensated at the differential amplifier, and the signal, Dro252 4, is realized at the output of the amplifier

porpion illumination. The current generators discharge partially the barrier capacitances 6 and thereby ensure the removal of phototransistors during impulse polling into the mode of high currents corresponding to small time constants. Generato. current тока current can discharge the capacitance 6 or constant (figure 2), or IMTG '

About the pulse current in the pauses between the pulses of the generator 11 of the survey, providing the value of the charge of holes, And 4-10 times greater than the value of the maximum charge of the photocurrent.

5 The proposed photoconverter provides a high threshold.

and photosensitivity (10 " ¹⁴ 10 ' ^1? J / element), a wide temperature range (from -60 to + 8θ“ θ) and θ high speed (10 ^_8 s), which expands the area of its application by

'compared with' famous.

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Claims (1)

A photoelectric semiconductor inverter containing a matrix of photosensitive cells, each of which is made on a device having a pn-junction, characterized in that, in order to increase speed, the threshold photosensitivity and the expansion of the temperature range, each cell is equipped with a second device that has a single device. and in each device, a Current generator is switched on parallel to the p-junction, and the outputs of the devices are connected to the inputs of a differential amplifier. | ё Fig, / 758252