Gain Bandwidth Engineering in Polymer Blends for Full‐Color‐Tunable Lasers

Abstract

Developing semiconductors with broad gain bandwidth has always been at the forefront of laser technologies. The variation in feedback resonators can provide a useful tool for producing a relatively wide range of discrete lasing wavelengths. However, the lasing wavelength range is limited by the fundamental gain bandwidth of the semiconductor itself. Gain bandwidth engineering for full‐color range lasing though remains a daunting challenge. Considering the abundant energy levels of organic semiconductors, the authors stride over the barrier of the gain bandwidth limitation and demonstrate the dynamically tunable amplification/lasing across the entire emission range by leveraging on Förster resonance energy transfer (FRET)‐assisted guest–host blends. The unprecedented tunability in amplification and lasing is governed by energy transfer process, which enables them to achieve wavelength‐tunable semiconductor lasers spanning the full visible region of the electromagnetic spectrum. Their distributed feedback (DFB) lasers using these guest–host blends as gain media cover almost all CIE color gamut (94%), which is 170% more perceptible colors than standard Red Green Blue color space. These insights can guide the versatile and convenient design of organic semiconductor materials transcending the current gain bandwidth limitation, paving the way for next generation of optoelectronic devices.

Effect of the cyano group on colour-tunability of aryl-substituted buta-1,3-diene based solid-state emissive copolymers

“…The development of solid-state organic based materials is the most promising owing to their excellent optoelectronic properties with versatile applications in the field of organic and polymeric light emitting diodes (OLEDs/PLEDs), [1][2][3][4][5][6][7][8] ultrasensitive sensors, [9][10][11] organic solid-state laser [12][13][14][15][16] and bio-imaging. [17][18][19] Additionally, organic materials have several advantages such as low cost, easy tunability, flexibility and simple fabrication over a large surface area.…”

Low Threshold, High Q-Factor Optically Pumped Organic Lasers and Exciton Dynamics in OLEDs under High Current Density: Singlet–Triplet Annihilation Effect and toward Electrical Injection Lasing

“…The dynamic signals at 423 nm wavelength are extracted and fitted by a three-exponential decay model, as shown in Figure 1c. 24 The ESA signal of the host overlaps with the SE signal of guest. For instance, the mCP:2 wt % PIO doped film shows a positive signal in the initial several picoseconds, which belongs to the ESA signal of 1d.…”

“…On the basis of the physical processes, the rise time of the SE signal can be regarded as the energy transfer lifetime (τ FRET ). The dynamic signals at 423 nm wavelength are extracted and fitted by a three-exponential decay model, as shown in Figure c . The ESA signal of the host overlaps with the SE signal of guest.…”

Device parameter to evaluate exciton energy transfer in organic whispering-gallery-mode microresonators and its dependence on the amplified spontaneous emission threshold

“…Dodabalapur and co-workers 36 reported ''broad tunability of the emission wavelength'' of the laser in doped films. Besides, other groups reported the effect of doping concentration on ASE spectra [37][38][39] and thresholds. 40 Moreover, Fo ¨rster transfer in doped films is widely used to assist laser emissions and/or ASEs in organic lasers.…”