In this study highly efficient nonradiative energy transfer from semiconductor quantum dots to monolayer MoS 2 with an efficiency of ~99% is demonstrated. Although the energy transfer efficiency is close to unity, there is little enhancement of the MoS 2 photoluminescence intensity. MoS 2 samples of varying layer thickness were electrically contacted and the optoelectronic performance of the devices was studied before and after adding quantum dots in a sensitizing layer. We find photocurrent enhancements as large as ~12 fold for monolayer MoS 2 devices and enhancements as high as ~4 fold for few layer devices with no change in the photocurrent with the MoS 2 devices of bulk-like thicknesses after adding the QDs