404 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. ED-28, NO. 4, APRIL 1981 nation velocity determination in Ina5Ga.SP/GaAs,’’ zyxwvut J. zyxwvutsrqpo Appl. Phys.,vol. zyxwvutsrqpon 48, no. 3, pp. 1288-1292,1977. [17] zyxwvutsrqpon C. G. Fonstad and C. A. Armiento, “Approximating the transient response of double-heterojunction devices,” J. Appl. Phys., vol. zyxwvuts [ 181 W. Harth, “Power output and rise time of light emitting diodes,” [19] zyxwvutsrqpo M. Ettenberg, H. Kressel, and J. P. Wittke, “Very high-radiance 49, pp. 2435-2438,1978. AEUE 30, no. 2, pp. 99-100,1976, .. edge-emitting LED,” IEEE J. Quant. Elecbon., $01. ?)E-12, pp. 360-364.1976. [20] D. J. Dumin,“Low-temperaturepropertiesofGalliumarsenide diodes,” Tech. Rep. 5107, Solid-state Electxonics Lab., Stanford Univ., 1964. [21] J. P. Arragon, “Practical limits of the modulation speed of light- emitting diodes,” 2nd Eur. Conf. Opt. Fibre Commun., Paris, p. 217,1976. [22] A. S. Grove, Physics and Technology of Semiconductor Devices. New York: Wiley, 1967, p. 227. [23] H. Melchior and M. J. 0. Strutt, “Small signal equivalent circuit of unsymmetrical junction diodes at high current densities,” IEEE Trans. Electron Devices., vol. ED-12, pp. 47-55, 1965. [24] V. I. Stafeev, “Effect of the resistance of the bulk of a semicon- Phys.-Tech. Phys., 3, pp. 1502-1512, 1958. ductor on the form of the current-voltagecharacteristic,” Sou. [25] W. Huberand J. Heinen,“Pulsebehaviorofdifferent types of GaAMs light-emitting diodes,” Solid State Electron zyx GB, 1, no. 2, [26] J. C. Bowers and S. R. Sedore, “SCEPTRE: A Computer Program for Circuit and Systems Analysis. Englewood Cliffs, NJ: Prentice Hall, 1971. [27] T. P. Lee and A. G. Dentai, “Power and modulation bandwidth of GaAs-AlGaAs high-radiance LED’s for optical communication systems,” IEEE J. Quant. Electron., vol. QE-14, p. 150-159, 1978. pp. 49-52. Monolithic GaAIAs/GaAs Infrared-to-Visible Wavelength Converter with Optical Power Amplification HEINZ BENEKING, SENIOR MEMBER, IEEE, NORBERT GROTE, AND MIKELIS N. SVILANS Abstract-A monolithic wavelength converter has been constructed in the GaAlAs alloy system which comprises a wide gap emitter photo- transistor and a double heterojunction (DH) light emitting diode (LED) in a bifacial configuration. The liquid phase epitaxy (LPE)-grown struc- ture is capable of efficiently converting IR light with h < 870 nm into the red spectral range in conjunction with optical power amplification. B I. INTRODUCTION Y EXPLOITING the wide range of band gap energies of 111-V semiconductors, optical wavelength conversion from the infrared to the visible part of the spectrum can be accom- plished with heterostructure systems involving narrow- and wide-band gap materials for the detection and emission of the radiation, respectively. This concept has been successfully fol- lowed up earlier in solid-state converters comprising p-n junc- tion photodetectors coupled in series with electroluminescent diodes. Wavelength down-conversion from 5.3 pm to 0.6- Manuscript received September 16, 1980; revised November 18, 1980. This work was supportedbythe Sonderforschungsbereich 56 “Festkorpereletronik.” H. Beneking and M. N. Svilans are with the institute of Semiconduc- tor Electronics, Aachen Technical University, Templergraben 55, D-5 100 Aachen, Federal Republic of Germany. N. Grote is with the “Heinrich-Hertz-institut fur Nachrichten- technik,” Berlin, West Germany. 0.7 pm in a pulsed integration mode was demonstrated with a circuit incorporating InSb and GaAsP [l] , whereas with a Ge-GaAs heterojunction a shift within the infrared region (1.5 pm to 0.9 pm) was realized, however, with low quantum efficiencies of 2.8 X lo-’ [2] . The Gal-,A1,As system, which due to its nearly perfect lattice match permits efficient implementation of the wave- length range covering the IR (870 nm) to the visible (670 nm) has been utilized for a wavelength converterconsisting of a diffused avalanche photodiode and a light emitting diode (LED) (A = 785 nm). The overall efficiency achieved was 1.5 X [3]. The conversion quantum efficiency reported so far, however, has not beensufficient to make the practical application of these devices feasible. In this work we describe the substantial improvementinthe overall efficiency of a wavelength con- verter, also denoted Anti-Stokes Converter (ASC), enabled by the inclusion of a bipolar wide gap emitter phototransistor with an LED on opposite sides of a substrate using liquid phase epitaxy (LPE). GaAlAs/GaAs phototransistors have recently been shown by other authors [4], [5] and our laboratory [6], [7] to be capable of providing high photocurrents at low bias voltages while maintaining a high sensitivity, which signifi- cantly exceeds the optical response of p-njunctionphoto- diodes by three orders of magnitude. 0018-9383/81/0400-0404$00.75 zyxwv 0 1981 IEEE