Browse Prior Art Database

Voltage Pulse Modulation of Photoluminescence

IP.com Disclosure Number: IPCOM000090205D
Original Publication Date: 1969-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Weiser, K: AUTHOR

Abstract

The photoluminescent device in A is formed of a body P-type GaP. Input light at a wavelength greater than the band-gap is applied to the diode. Control voltages are applied between the two electrodes. The variance in the current voltage characteristic for the device when light is applied is shown in B. The change in photoluminescent output when a voltage pulse is applied is shown in C and D. First, as in C, when a short voltage pulse (0.1 mu sec.) is applied (t(1)), there is a sharp increase in the photoluminescent output which persists for a considerable time after the pulse is terminated. As shown in D, there is also a shift in the wavelength of the output light to shorter wavelengths (curve a to curve b) when a short voltage pulse is applied and this shift also persists for a significant time after pulse termination.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 90% of the total text.

Page 1 of 2

Voltage Pulse Modulation of Photoluminescence

The photoluminescent device in A is formed of a body P-type GaP. Input light at a wavelength greater than the band-gap is applied to the diode. Control voltages are applied between the two electrodes. The variance in the current voltage characteristic for the device when light is applied is shown in B. The change in photoluminescent output when a voltage pulse is applied is shown in C and D. First, as in C, when a short voltage pulse (0.1 mu sec.) is applied (t(1)), there is a sharp increase in the photoluminescent output which persists for a considerable time after the pulse is terminated. As shown in D, there is also a shift in the wavelength of the output light to shorter wavelengths (curve a to curve
b) when a short voltage pulse is applied and this shift also persists for a significant time after pulse termination. The device is operated at a temperature at which the holes are bound to acceptor centers. The temperature depends on the material. The results above are for a temperature 27 degrees K. This effect is produced in semiconductor crystals of materials such as GaP, Si and AlSb where the radiation output is of the pair radiation type, that is, by transitions between paired donors and acceptors. The applied voltage pulse provides a transfer of holes from acceptors far away from donors to acceptors near donors. This increases the pair population and the radiative output which is also shifted to a lower wavelen...