Bi‐Induced Electron Concentration Enhancement Being Responsible for Photoluminescence Blueshift and Broadening in InAs Films

Abstract

Photoluminescence (PL) study is conducted on InAs films molecular beam epitaxially grown on GaAs substrates with different Bi flux levels. A PL peak blueshift accompanied by linewidth broadening is found with the increase of Bi/As flux ratio, in contrast to the common Bi isoelectronic incorporation or surfactant effect. It is, with detailed lineshape analysis and the evidence of PL peak splitting in a magnetic filed, attributed to the electron concentration enhancement induced by Bi flux. The electron concentration in InAs film is evaluated, which is about 5‐fold enhanced as Bi/As flux ratio rises up from 0 to 1 × 10−3. The temperature dependence of the PL spectrum indicates that the carrier redistribution augments while the carrier–phonon Fröhlich scattering weakens in InAs films with high Bi/As flux ratios. These findings reveal a novel Bi effect of electron concentration enhancement, and contribute to the basic knowledge of Bi in III–V semiconductors.

The roles of Bi in InAs and InAsBi nanostructure growth

“…Surprisingly, no clear Bi signal is detected. This may be attributed to the surfactant effect of Bi 30,[34][35][36][37][38] and the extremely small amount of Bi incorporation may be beyond the EDS detection range (around or less than 1%), which is further evidenced by photoluminescence (PL) measurement (Fig. S3, ESI †).…”