Effects of epitaxial lift-off on interface recombination and laser cooling in GaInP∕GaAs heterostructures

Abstract

Photoluminescence of GaAs passivated with GaInP is studied over the temperature range 7-450 K. Different photocarrier recombination mechanisms are identified as the temperature changes. An interface recombination velocity of less than 0.6 cm/ s is measured at 300 K. Lift-off processing inhibits but does not preclude laser cooling of GaAs.

Laser cooling of solids

“…Laser cooling of semiconductors has been examined theoretically [15,44,45,[47][48][49][50][51][52] as well as in experimental studies [46,[53][54][55][56]. A feasibility study by the authors outlined the conditions for net cooling based on fundamental material properties and light management [15].…”

“…The loss terms (A and C coefficients) decrease while the radiative rate (B coefficient) increases inversely with lattice temperature. Using the accepted scaling for C(T)∝exp(-β(300/T-1)) with β ≈2.4 for GaAs [55,69], taking B ∝ T −3/2 [59,70], keeping hν f /hν − 1 ≈ k B T/E g , and ignoring parasitic losses and the small temperature dependence of the band-gap energy, we obtain for the break-even nonradiative decay rate At T = 150 K, for example, the break-even lifetime is lowered by ∼ 40 times compared with the room temperature (T = 300 K) condition. This is visualized by plotting η ext versus T as is shown in Fig.…”

“…The optimum GaAs thickness is found to be about 1 μm, determined by balancing excessive luminescence re-absorption for thicker layers with dominant surface recombination for thinner layers. [55,82]. The measured temperature dependence of EQE is depicted in Fig.…”

Advances in laser cooling of semiconductors

“…We have extensively studied GaAs heterostructure systems and characterize their nonradiative lifetime (τ nr =1/A) and external quantum efficiency (EQE) for various growth techniques as a function of temperature and active-layer thickness. 26 We have also investigated various techniques for enhancing luminescence extraction efficiency (η e ). 36,37 .…”

A design of a PhC-enhanced LED for electroluminescence cooling

“…31 Semiconductors are also attractive and promising materials for optical refrigeration. [32][33][34][35] One of the most intensively studied semiconductor devices for optical refrigeration are GaAs based quantum wells, whose EQE can be as high as 99.5%. 36,37 However, due to strong parasitic absorption, net cooling has not been achieved in III-V quantum wells.…”