Interface polarons in a realistic heterojunction potential

The multi‐quantum‐barrier electron blocking layer (EBL) is reported to significantly improve efficiency by nearly 3 times over a single barrier in deep‐UV AlGaN light‐emitting diodes to deal with electron leakage. The improvement is usually attributed to the enhanced effective barrier height, and this article aims to explore the benefits of the tunneling effect by calculating the tunneling currents of electrons and holes through an Al0.6Ga0.4N/AlyGa1−yN double‐barrier EBL under external bias from opposite directions. The results show that the tunneling current for holes Jh is several orders of magnitude higher than that of the electrons Je as the barriers are with Al mole fraction y greater than 0.75 and thickness larger than 2 nm, which promises effective hole injection by tunneling without much electron leakage. Tunneling mechanism works better in EBL with higher and thicker barriers because the tunneling coefficients of light hole drop much slower than electrons due to its small effective mass. A proper distance between the barriers is needed to avoid electron leakage while holes tunnel through the EBL. Built‐in electric fields tilt the band to enlarge the peak‐to‐valley ratio. This work indicates that the tunneling effect substantially facilitates a multibarrier EBL to enhance carrier‐injection efficiency.

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“…[15], in eV), and ε 0 and ε ∞ are the static and optical dielectric constants (from Ref. [11] increase of exciton-LO-phonon coupling. Near P t the excitons and LO phonons may have strong interaction due to E b ≈ LO ω and another elementary excitation will form.…”

Section: Strain Dependence Of the Lo Phonon Frequenciesmentioning

confidence: 99%

“…[10], in GPa), m* e (from Ref. [11]) and m* hh (from Ref. [15]) are the effective masses of the electron and the heavy hole (in units of the free electron mass), E g0 is the energy band gap (from Ref.…”

Section: Strain Dependence Of the Lo Phonon Frequenciesmentioning

confidence: 99%

Pressure‐induced increase of exciton–LO‐phonon coupling in a ZnCdSe/ZnSe quantum well

Guo

Liang

Ban

2003

Physica Status Solidi (b)

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The possibility of pressure-induced increase of exciton-LO-phonon coupling in ZnCdSe/ZnSe quantum wells is studied. The ground state binding energies of the heavy hole excitons are calculated using a variational method with consideration of the electron-phonon interaction and the pressure dependence of the parameters. The results show that for quantum wells with intermediate well width, the exciton binding energy and the LO-phonon energy may coincide in the course of pressure increasing, resulting in the increase of exciton-LO-phonon coupling. It is also found that among the pressure-dependent parameters, the influence of the lattice constant is the most important one. The changes of both the effective masses and the dielectric constants have obvious effects on the exciton binding energy, but their influences are counterbalanced.

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Interface polarons in a realistic heterojunction potential

Cited by 30 publications

References 0 publications

Hot-electron energy-loss rate via PO-phonon scattering in CdZnSe/ZnSe quantum wire

Hot-electron energy-loss rate via PO-phonon scattering in CdZnSe/ZnSe quantum wire

Resonant Tunneling Effects on the Double‐Barrier Electron Blocking Layer of a Nitride Deep‐UV Light‐Emitting Diode

Pressure‐induced increase of exciton–LO‐phonon coupling in a ZnCdSe/ZnSe quantum well

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