Fig. 4: Electric field-induced decrease of oscillator strength in CdxZn1-xSe-ZnS QDs.
From: Strong high-energy exciton electroluminescence from the light holes of polytypic quantum dots
a Voltage-dependent steady state Electrically excited transient absorption (EETA) spectra of CdxZn1-xSe-ZnS QD-LEDs, averaged within the 10th microsecond. HH: heavy hole; LH: light hole; Pe: higher-order electron state; 2Sh: higher-order hole state. b Amplitude of band-edge state bleaching versus voltage. The increase in amplitude indicates an increasing averaged electron population 〈Ne〉. c Absorbance spectra under different reversed biases. d Normalized absorbance of LH (green, squares) and HH (purple, circles), as a function of bias. e The x-axis cross-section of HH (purple) and LH (green) wavefunctions under an x-direction electric field (500 kV cm−1). The relative directions of the QD and the field are indicated by the schematic. The deformation of potential wells is represented in a dashed line. f Normalized wavefunction overlaps \(\frac{{\left\langle {\psi }_{{{{{\rm{e}}}}}}|{\psi }_{{{{{\rm{h}}}}}}\right\rangle }_{{{{{\bf{E}}}}}}}{{\left\langle {\psi }_{{{{{\rm{e}}}}}}|{\psi }_{{{{{\rm{h}}}}}}\right\rangle }_{0}}\) of LH-electron (green) and HH-electron (purple) as a function of the electric field.
