Color enrichment solids of spectrally pure colloidal quantum wells for wide color Span in displays

Abstract

Colloidal quantum wells (CQWs) are excellent candidates for lighting and display applications owing to their narrow emission linewidths (<30 nm). However, realizing their efficient and stable light-emitting solids remains a challenge. To address this problem, stable, efficient solids of CQWs incorporated into crystal matrices are shown. Green-emitting CdSe/CdS core/crown and red-emitting CdSe/CdS core/shell CQWs wrapped into these crystal solids are employed as proof-of-concept demonstrations of light-emitting diode (LED) integration targeting a wide color span in display backlighting. The quantum yield of the green- and red-emitting CQW-containing solids of sucrose reach ≈20% and ≈55%, respectively, while emission linewidths and peak wavelengths remain almost unaltered. Furthermore, sucrose matrix preserves ≈70% and ≈45% of the initial emission intensity of the green- and red-emitting CQWs after >60 h, respectively, which is ≈4× and ≈2× better than the drop-casted CQW films and reference (KCl) host. Color-converting LEDs of these green- and red-emitting CQWs in sucrose possess luminous efficiencies 122 and 189 lm W−1elect, respectively. With the liquid crystal display filters, this becomes 39 and 86 lm W−1elect, respectively, providing with a color gamut 25% broader than the National Television Standards Committee standard. These results prove that CQW solids enable efficient and stable color converters for display and lighting applications.