6533b7d5fe1ef96bd126494c
RESEARCH PRODUCT
High-pressure optical absorption in InN: Electron density dependence in the wurtzite phase and reevaluation of the indirect band gap of rocksalt InN
B. García-domeneR. OlivaAlfredo SeguraJordi IbáñezTomohiro YamaguchiYasushi NanishiLuis ArtúsFrancisco Javier Manjónsubject
Electron densityPhase transitionMaterials scienceCondensed matter physicsBand gapCondensed Matter PhysicsPressure coefficientIII-V NitridesElectronic Optical and Magnetic MaterialsFISICA APLICADAAlloysDirect and indirect band gapsAbsorption (logic)StabilityEnergy (signal processing)Wurtzite crystal structuredescription
We report on high-pressure optical absorption measurements on InN epilayers with a range of free-electron concentrations (5×1017–1.6×1019 cm−3) to investigate the effect of free carriers on the pressure coefficient of the optical band gap of wurtzite InN. With increasing carrier concentration, we observe a decrease of the absolute value of the optical band gap pressure coefficient of wurtzite InN. An analysis of our data based on the k·p model allows us to obtain a pressure coefficient of 32 meV/GPa for the fundamental band gap of intrinsic wurtzite InN. Optical absorption measurements on a 5.7-μm-thick InN epilayer at pressures above the wurtzite-to-rocksalt transition have allowed us to obtain an accurate determination of the indirect band gap energy of rocksalt InN as a function of pressure. Around the phase transition (∼15 GPa), a band gap value of 0.7 eV and a pressure coefficient of ∼23 meV/GPa are obtained.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-07-24 | Physical Review B |