Growth and characterization of InAs quantum dots with low-density and long emission wavelength

The growth parameters affecting the deposition of self-assembled InAs quantum dots (QDs) on GaAs substrate by low-pressure metal-organic chemical vapor deposition (MOCVD) are reported. The low-density InAs QDs (～ 5 × 108 cm-2) are achieved using high growth temperature and low InAs coverage. Photolu-minescence (PL) measurements show the good optical quality of low-density QDs. At room temperature,the ground state peak wavelength of PL spectrum and full-width at half-maximum (FWHM) are 1361 nm and 23 meV (35 nm), respectively, which are obtained as the GaAs capping layer grown using triethylgallium (TEG) and tertiallybutylarsine (TBA). The PL spectra exhibit three emission peaks at 1361, 1280,and 1204 nm, which correspond to the ground state, the first excited state, and the second excited state of the QDs, respectively.