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 sub- strate by low-pressure metal-organic chemical vapor deposition（MOCVD）are reported,The low-density InAs QDs(～5×10;cm;)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 triethylgal- lium（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.