A high performance transparent inverted organic light emitting device with a total maximum luminance efficiency of 67 cd A⁻¹ and power efficiency of 67 lm W⁻¹ was realized using 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (HATCN) as an organic buffer material. HATCN, a discoid organic molecule, effectively protected the underlying organic emission layers from damage caused by sputter deposition of the indium zinc oxide top electrode, and simultaneously showed good hole injection performance from the transparent top electrode into an organic hole transporting layer. Moreover, transparent inverted OLEDs show an average transmittance of around 81% in the visible range; this value is very close to that of ITO/glass itself.