Formation of excitons from free electron–hole pairs due to acoustic phonon interactions in quantum wells

✍ Scribed by I.-K. Oh; Jai Singh

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 168 KB
• Volume: 30
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.2001.1001

✦ Synopsis

A study of the process of exciton formation due to acoustic phonon interaction in quantum wells (QWs) is presented. Considering that excitons are formed from photoexcited free electron-hole pairs, we have derived the rate of such formation as a function of density and temperature of charge carriers and wavevector K || of the center-of-mass motion of exciton, and finally applied our theory to GaAs/AlGaAs QWs. We have found that the formation of an exciton due to acoustic phonon emission is more efficient at relatively large values of K || (hot excitons) whereas that due to longitudinal optical (LO) phonon emission is more efficient at relatively small values of K || .