Towards efficient mid-IR LED operation: optical pumping, extraction or injection of carriers?

Abstract

Positive and negative output power, spectral and current—voltage characteristics of the In(Ga)As and InAs(Sb) based heterostructure light-emitting diodes with the ‘episide-down’ construction grown onto heavily doped n⁺-InAs have been examined in the 20-200°C temperature range. Optically pumped LEDs composed from the above heterostructures or from InSb exhibited output characteristics fairly close to the conventional LEDs. Wavelength and temperature variation of the emission power in the 3.3–8 μm spectral range was compared with the phenomenological model based on the expectations of the negative luminescence power (NLP) and saturation current (I _sat). The crossover of forward bias power at 1 A and negative power at I = I _sat takes place at 90 and 160°C for 5.3 and 4.3 μm LEDs correspondingly.