Quantum Dot Display Science and Technology

Chapter 1Physics and Photophysics of Quantum Dots for Display Applications

Einav Scharf, Uri Banin

Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, Israel

1.1 Introduction

Semiconductor quantum dots (QDs) are nanocrystals composed of hundreds to thousands of atoms, forming a lattice of nanometric size. They exhibit highly bright and stable emission, with color tunable via size, composition, and shape, and can achieve fluorescence quantum efficiency approaching unity [1]. These qualities along with their narrow emission linewidth make them prominent building blocks for display applications. The unique characteristics of QDs already enhance the properties of existing display technologies, and with further developments, they are bound to penetrate display device technologies even to greater extent. In this chapter, we will review briefly the fundamental principles governing the optoelectronic characteristics of such QDs, serving as a basis for their utility in displays.

1.2 Quantum Confinement and Band Structure

The electronic structure of semiconductor QDs manifests a manifold of fully occupied valence band (VB) states and a manifold of empty conduction band (CB) states, separated by the bandgap. Excitation of the QD, for example, by the absorption of a photon, promotes an electron to the CB, leaving an electron vacancy, a hole, in the VB. This electron–hole pair, termed as an exciton, is bound by Coulomb ...