Excitons in InP at high excitation levels

Abstract

The possibility of observing collective effects of electrons and holes in InP under intense optical irradiation from GaAs lasers is examined. At 2°K, the exciton density at which a postulated Bose-Einstein condensation might occur is 1.3×1015 cm-3. It is shown that at this density another collective effect (shielding of the Coulomb otential) may cause excitons to dissociate. However, the criterion for exciton dissociation is too crude to resolve this question. The requisite light intensity to observe the effects discussed is estimated to be ∼5-100 W/cm2, whereas intensities ∼104 W/cm2 are available over a spot with diameter 0.1 mm. © 1965 The American Institute of Physics.