Effect of Thickness of CeF3 Layer on Electroluminescence Spectra of n‐Si/Diamond/CeF3/ITO Composite Films

Abstract

A series of n‐Si/diamond/CeF3/ITO composite film electroluminescence (EL) devices are made, and it is found that their EL spectra and EL intensities vary with the thickness of the CeF3 layer. For EL devices with a CeF3 layer thickness less than 500 nm, the EL spectrum is mainly concentrated in the blue and red areas. When the thickness of CeF3 exceeds 500 nm, the EL spectra of devices are primarily focused on the green and red areas. As the thickness of the CeF3 film increases (from 100 to 220 nm), the brightness of the EL device increases to the maximum (9 cd m−2, approximately pure blue luminescence); meanwhile, the intensity ratio between the blue peak and red peak also increases from 1.67 to 3.57 (maximum). As the thickness of CeF3 continues to grow (from 220 to 500 nm), the brightness of EL devices decreases gradually, and the intensity ratio between the blue peak and red peak decreases from 3.57 to 0.37. When the thickness of CeF3 increases to 700 nm, the corresponding brightness of the EL device reduces to 5 cd m−2 (minimum). Meanwhile, the blue peak (440 nm) shifts to the green area (524 nm).