Applied Physics Letters, v.79, issue 25, p. 4228-4230, December 17

CURRENT CROWDING IN InAsSb LED STRUCTURES

V. K. Malyutenko, O.Yu.Malyutenko, A. D. Podoltsev, I.N.Kucheryavaya, B. A. Matveev, M. A. Remennyi, N. M. Stus

High-resolution two-dimensional infrared (IR) imaging of dynamic electronic processes in the surface-emitting p-InAsSb/n-InAsSbP light-emitting diodes (LEDs) (4.3 µm, T>300 K) showed that forward current crowding drastically decreases efficiency of LEDs with point contacts. Current flows and IR emittance "forget" the emitting area size and geometry, whereas extended areas far off the point contacts become even "darker" with the current increase. Contrary to this, the reverse bias causes remarkable current spreading and uniform "negative emittance" distribution. Therefore the negative luminescence mode is more favorable for IR LEDs operating at higher temperatures.