Apparatus and method for modulating photon output of a quantum dot light emitting device

An apparatus is provided for modulating the photon output of a plurality of free standing quantum dots. The apparatus comprises a first electron injection layer (210, 310, 410) disposed between a first electrode (212, 312, 412) and a layer (208, 308, 408) of the plurality of free standing quantum dots. A hole transport layer (206, 306, 406) is disposed between the layer (208, 308, 408) of the plurality of quantum dots and a second electrode (204, 304, 404). A light source (224, 324, 424) is disposed so as to apply light to the layer (208, 308, 408) of the plurality of free standing quantum dots. The photon output of the layer (208, 308, 408) of the plurality of free standing quantum dots is modulated by applying a voltage to the first and second electrodes (212, 312, 412, 204, 304, 404). Electrons excited to a higher energy state within layer (208, 308, 408) of the free standing quantum dots by the light source (224, 324, 424) are prevented from returning to a lower state by electrons from the electric field of the applied voltage, and therefore the free standing quantum dots are prevented from emitting a photon. The voltage source (216, 316, 416) may be modulated to vary the photon output.