Red electroluminescence behavior of CdSe/CdZnS core-shell quantum dots between hole transport layer (PEDOT:PSS) and electron transport layer (TPBi) were investigated. Colloidal CdSe/CdZnS core-shell quantum dots by capped with long-chain amine showed the red photoluminescence with 644 nm peak wavelength and 602 nm absorption peak. In this article, This device’s turn-on voltage is 8 V. As an increase of applied voltages, current densities and luminances are exponentially increased. The red electroluminescence spectra were red shifted from 629 nm peak wavelength at 11 V to 645 nm peak wavelength at maximum voltage of 17 V, and their widths were broadened from 44.6 nm at 11 V to 52.3 nm at 17 V.