The forward and reverse current-voltage characteristics of amorphous silicon p-n junction diodes are presented as a function of doping level. A study of the forward characteristics with temperature show that at high doping levels the current is limited by tunnelling through the depletion region via gap states. At the lowest doping levels the diode current is determined by generation-recombination in the depletion region. A similar interpretation is applied to the reverse characteristics. These results are relevant to the use of these diodes both as nonlinear elements in matrix-addressed large-area liquid-crystal displays and thin-film solar cells.

A solar ultraviolet detector prototype for the GOES spacecraft has been calibrated using the X24C beamline at the Brookhaven NSLS. Similar in design to the 3-channel 50110 CELIAS SEM, the GOES EUV uses a combination of transmission gratings and silicon photodiodes with thin-film metal overcoats to provide the required bandpasses. Four of the channels position the photodiodes at the first to fourth orders of 2500 and 5000 L/mm transmission gratings to provide spectral information over four wavelength bands from approximately 5-80 nm. The fifth channel positions the photodiode at first order of a 1667 L/mm transmission grating in combination with a bandpass filter centered at approximately 120 nm to provide coverage in the Lyman alpha region of the solar spectrum. The GOES EUV will provide continuous monitoring of solar EUV in bandpasses that are known to have a large variability in the amount of energy deposition in the earth's ionosphere over a solar cycle. Prototype detector design and calibration procedure are discussed. Absolute responses of the design model and synchrotron beamline properties relevant to calibration are presented.

A theory is presented which relates that current, voltage, and light characteristics of SiC p—ν—n diodes and which applies to transient and de conditions. Based on a simple model, the theoretical predictions compare favourably with a series of measurements made on a four contact diode from which the components of the current—voltage, light—current, and light—voltage plots are readily identified. The sublinear light—current response of these diodes is attributed to injection into the diffusion regions with power law non‐radiative recombination rates; the long light decay is governed by the recombination of the hole minority carriers in the ν diffusion region.

The operation of SiC LEDs studied as a function of temperature between 245 and 400 K correlates with the p–ν junction model proposed earlier. A comparison of characteristics is made when the polytype is changed from 6H to 4H and when the quantity of tungsten in the growth region is varied. The blue‐green emission is related to the secondary diffusion effect and oxygen appears to be responsible for producing these effect in vapour epitaxy diodes.

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