nAnotEcHnoLoGY Heterojunction Photovoltaics Using Printed colloidal Quantum Dots as the Photosensitive Layer

Colloidal quantum dot (QD) systems offer distinct optical and electronic properties that are not easily attained by other nanostructured semiconductors, such as highly saturated emission in QD light-emitting-diodes, access to infrared radiation in QD photodetectors, and the prospect of optically optimized solar cell structures [1]. The prevailing deposition method for colloidal QD systems is spin-casting, which introduces limitations such as solvent incompatibility with underlying films and the inability to pattern side-by-side pixels for multispectral photodetector arrays. In the present work we employ a non-destructive microcontact printing method [2], which allows for deposition of a thin quantum dot film onto a wide-band-gap organic hole transport layer, N,N'-Bis (3-methylphenyl)-N,N'-bis-(phenyl)-9,9-spiro-bifluoren