High light-quality OLEDs with a wet-processed single emissive layer

Abstract

High light-quality and low color temperature are crucial to justify a comfortable healthy illumination. Wet-process enables electronic devices cost-effective fabrication feasibility. We present herein low color temperature, blue-emission hazards free organic light emitting diodes (OLEDs) with very-high light-quality indices, that with a single emissive layer spin-coated with multiple blackbody-radiation complementary dyes, namely deep-red, yellow, green and sky-blue. Specifically, an OLED with a 1,854 K color temperature showed a color rendering index (CRI) of 90 and a spectrum resemblance index (SRI) of 88, whose melatonin suppression sensitivity is only 3% relative to a reference blue light of 480 nm. Its maximum retina permissible exposure limit is 3,454 seconds at 100 lx, 11, 10 and 6 times longer and safer than the counterparts of compact fluorescent lamp (5,920 K), light emitting diode (5,500 K) and OLED (5,000 K). By incorporating a co-host, tris(4-carbazoyl-9-ylphenyl)amine (TCTA), the resulting OLED showed a current efficiency of 24.9 cd/A and an external quantum efficiency of 24.5% at 100 cd/m2. It exhibited ultra-high light quality with a CRI of 93 and an SRI of 92. These prove blue-hazard free, high quality and healthy OLED to be fabrication feasible via the easy-to-apply wet-processed single emissive layer with multiple emitters.

Highly Efficient Candlelight Organic Light-Emitting Diode with a Very Low Color Temperature

“…Furthermore, a comparatively studied and reported candlelight organic LEDs showing their fabrication method, color temperature, power efficacy, current efficacy, and the respective references are revealed in Table S2. The reported color temperature (at 100 cd/m 2 ) for the solution and dry-processed candlelight organic LED devices against current efficacy and power efficacy [2,4,5,7,11,12,17,18,21,64,65].…”

“…Figure7. The reported color temperature (at 100 cd/m 2 ) for the solution and dry-processed candlelight organic LED devices against current efficacy and power efficacy[2,4,5,7,11,12,17,18,21,64,65].…”

Exciplex-Forming Systems of Physically Mixed and Covalently Bonded Benzoyl-1H-1,2,3-Triazole and Carbazole Moieties for Solution-Processed White OLEDs

“… 23 , 24 It is also a known fact that to realize high CRI, a WOLED should have an as broad as possible emission spectrum. 25 , 26 Ultra-high CRI is important for lighting applications in museums, art galleries, and other commercial places. Great developments in efficient white OLEDs with a CRI value higher than 90 were recently observed.…”

Recent advances in efficient emissive materials-based OLED applications: a review

“…This versatility makes it different from other optoelectronic devices like CRT, SSD, and LED. OLED technology becomes a challenging scheme for many multinational electronics corporations (such as LG display, Samsung mobile display, Philips, and General Electric) [35,36]. OLEDs have many advantages over other lighting and display devices, but in parallel, they have few limitations as follows: OLEDs can be easily damaged by water, they still have high cost, and they are difficult to be fabricated, and they have a limited life span [37].…”