Optical transitions in symmetric, compositionally graded triangular AlGaAs quantum wells grown by molecular beam epitaxy

Abstract

Articles you may be interested inElectrical characteristics of symmetric, compositionally graded triangular heterostructure diodes grown by molecular beam epitaxy

Properties of Strain Compensated Symmetrical Triangular Quantum Wells Composed of InGaAs/InAs Chirped Superlattice Grown Using Gas Source Molecular Beam Epitaxy

“…The best fit with Γ i = 25.6 meV, Γ LA = 0.023 meV/K, Γ LO = 59.4 meV is shown in the inset Figure 4. The inhomogeneous part (Γ i ) of 25.6 meV is much narrower than that of 44 meV reported in symmetrical triangular MQW grown via the analogue alloy method, [14] primarily due to the higher growth rates and hence the decreased incorporation of background contaminants of digital alloy method. On the other hand, Γ i in our case is larger than that reported in most rectangular MQW.…”

“…[12] On the other hand, an increase of the optical efficiency could be expected by using a triangular shaped well as more photoexcited carriers are swept into the wells by the built-in electric field. [13] To construct triangular QWs, two methods could be used in practice, one is the analogue alloy method [14] in which the source intensity is changing gradually at extremely low growth rate (e.g. about 30 nm/h), the other is the digital alloy method, [15−18] which approximates the compositional graded well profile by using chirped superlattice (SL) of two different materials at digitally setting thicknesses, the latter is much convenient for molecular beam epitaxy (MBE) as in this case the growth rate keeps normal.…”

Room-temperature photoresponse of Schottky photodiodes based on GaNxAs1−x synthesized by ion implantation and pulsed-laser melting

“…This is reasonable, because for a GaN x As 1−x alloy with a nonuniform nitrogen concentration profile, the PC threshold values tend to be more sensitive to the lowest band gap region; whereas in PR measurements the model fitting has been known to collectively reflect the graded band-gap structure. 13 To summarize, we have demonstrated engineered nearinfrared photoresponse of Schottky photodiodes based on HMA GaN x As 1−x , synthesized using N ion implantation followed by pulsed-laser melting and RTA. We succeeded in redshifting the GaAs responsivity onset by 250 meV to ϳ1.18 eV ͑from 870 to 1050 nm͒, showing the potential of developing optoelectronic devices via synthesis routes based on energetic ion and photon beams.…”

Elastic waves in graded-composition systems

“…The x value in each step was controlled by the Al source temperature. Other profiles having parabolic [19] and linear [20][21][22][23][24] variations have also been grown.…”