Orientation effect on intersubband tunneling of quantum wells grown on high-index GaAs(n11)A (n≤4) substrates

✍ Scribed by J.M Feng; K Asai; Y Narukawa; Y Kawakami; S Fujita; T Ohachi

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 436 KB
• Volume: 159-160
• Category: Article
• ISSN: 0169-4332
• DOI: 10.1016/s0169-4332(00)00133-1

✦ Synopsis

The effect of the orientation on intersubband tunneling process in Al Ga AsrGaAs asymmetric double quantum 0.35 0.65 Ž . Ž . Ž . Ž . wells ADQWs grown on GaAs n11 A n F 4 substrates was studied by cw photoluminescence PL , time-resolved Ž . Ž . photoluminescence TRPL at low temperatures and transmission electron microscope TEM measurements. The red-shift Ž . Ž . of two PL peaks from the wide quantum well WW and the narrow quantum well NW for substrate orientation far from

Ž . the 100 plane is attributed to the large anisotropy of the heavy-hole band in the different GaAs orientations. TRPL Ž . Ž . experimental results show the decay time t of the excitation from the NW is about 100 ps for 111 A and 211 A samples, which is 50% smaller than that of the other samples. This fast tunneling process may be understood such that the large Ž . Ž . anisotropy of the heavy-hole band for 111 A and 211 A planes causes the resonant tunneling of holes between the WW and NW. The optical transition dependence of the orientation in ADQWs provides a useful method to estimate the tunneling time of holes through a barrier.