Quantum well

About: Quantum well is a research topic. Over the lifetime, 44627 publications have been published within this topic receiving 674023 citations. The topic is also known as: QW & quantum potential well.

Normal incidence hole intersubband absorption long wavelength GaAs/AlxGa1−xAs quantum well infrared photodetectors

Abstract: The first long wavelength quantum well infrared photodetector based on valence band intersubband absorption holes is demonstrated. A normal incidence quantum efficiency of η=28% and detectivity of D*λ=3.1×1010 cm √Hz/W at T=77 K, for a cutoff wavelength λc=7.9 μm, have been achieved.

InGaAs/AlGaAs strained single quantum well diode lasers with extremely low threshold current density and high efficiency

Abstract: Graded‐index separate‐confinement heterostructure InGaAs/AlGaAs single quantum well diode lasers emitting at 1.02 μm have been fabricated from structures grown by organometallic vapor phase epitaxy. Under pulsed operation, threshold current densities as low as 65 A/cm2, the lowest reported for InGaAs/AsGaAs lasers, have been obtained for a cavity length L of 1500 μm. Differential quantum efficiencies as high as 90% have been obtained for L=300 μm. Output powers as high as 1.6 W per facet and power conversion efficiencies as high as 47% have been obtained for continuous operation of uncoated lasers with L=1000 μm.

Low-threshold-current-density 1300-nm dilute-nitride quantum well lasers

Abstract: Metalorganic chemical vapor deposition-grown In0.4Ga0.6As0.995N0.005 quantum well (QW) lasers have been realized, at an emission wavelength of 1.295 μm, with threshold and transparency current densities as low as 211 A/cm2 (for L=2000 μm) and 75 A/cm2, respectively. The utilization of a tensile-strained GaAs0.67P0.33 buffer layer and GaAs0.85P0.15 barrier layers allows a highly-compressively-strained In0.4Ga0.6As0.995N0.005 QW to be grown on a high-Al-content lower cladding layer, resulting in devices with high current injection efficiency (ηinj∼97%).

Continuous‐wave operation of InGaN multi‐quantum‐well‐structure laser diodes at 233 K

Abstract: Continuous‐wave (cw) operation of InGaN multiquantum‐well‐structure laser diodes (LDs) was demonstrated at 233 K. The threshold current and voltage of the LD were 210 mA and 11 V, respectively. During room‐temperature cw operation, the LDs were easily broken within one second due to heat generation. At 233 K, the lifetime of the LDs was longer than 30 min, and the emission spectra could be measured under cw operation. Only a single peak was observed under cw operation with increasing forward current above the threshold current. The characteristic temperature of the threshold current of the LDs was 162 K.

Unexpected transition from single to double quantum well potential induced by intense laser fields in a semiconductor quantum well

Abstract: When an electronic system is irradiated by an intense laser field, the potential “seen” by electrons is modified, which affects significantly the bound-state energy levels, a feature that has been observed in transition energy experiments. For lasers for which the dipole approximation applies, a nonperturbative approach based upon the Kramers–Henneberger translation transformation, followed by Floquet series expansions, yields, for sufficiently high frequencies, the so-called “laser-dressed” potential, which is taken for composing a time-independent Schrodinger equation whose solutions are the desired quasistationary states. This approach, developed originally for atoms, has been verified to be useful also for carriers in semiconductor nanostructures under intense laser fields. In quantum wells, analytical expressions for the dressed potential have been proposed in literature for a nonresonant, intense laser field polarized perpendicularly to the interfaces. By noting that they apply only for α0≤L/2, wher...