Figure 6 .
Optical images and room-temperature EL spectra of the GNR/SNW heterojunction LEDs. (a, b, c) The optical images of the GNR/SNW (ZnO, CdS, CdSe, respectively) heterojunction LEDs at a forward bias of 5 V. Dashed lines were used to demarcate the graphenes from the substrates. White arrows: the light collecting points during the EL measurements. (d, e, f) Room-temperature EL spectra for GNR/SNW (ZnO, CdS, CdSe, respectively) heterojunction LEDs at various forward biases.
Ye et al. Nanoscale Research Letters 2012 7:218 doi:10.1186/1556-276X-7-218