Transparent displays are attracting more and more attentions nowadays, benefited from its widely application in TVs, automobiles and shopwindows. Dual emission Organic Light Emitting Devices (OLEDs) are efficient solution to increase the transmittance of OLED displays, while the device efficiency is always low. Here we introduce a thin metal film to enhance the device efficiency by building a weak micro‐cavity. To further increase the efficiency, lifetime and maximum luminance, tandem device is established with the efficiency comparable to single top emission device