Theory of the perfect lens

Zhang, Xuhuai; Forrest, Stephen R.

doi:10.1103/physrevb.84.045427

Cited by 70 publications

(104 citation statements)

References 51 publications

Supporting

Mentioning

100

Contrasting

Unclassified

Order By: Relevance

“…Finally, k hg = 4 × 10 10 s -1 is obtained from Ref. [10]. Figure 2 shows the result of fits that yield N 0 , k ST , and k ISC from the PL transients in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Figure 4(b) shows a minor change of guest triplet absorption across the spectral region of the probe. For simplicity of analysis, the average triplet absorption coefficient is converted to the triplet density when divided by the DCM2 guest triplet absorption cross section of 4 × 10 -17 cm 2 [10]. The normalized guest triplet density in DCM2:Alq 3 vs.…”

Section: Resultsmentioning

confidence: 99%

“…IV. Also, N 0 is the guest triplet saturation density [10], k hg is the pre-factor for host-guest Dexter transfer, and L is the effective localization radius of the exciton on the molecule (~1 nm) [10]. The triplet decay rate includes the triplet natural decay (k T ) and TTA.…”

Section: Theorymentioning

confidence: 99%

“…via a Dexter process). The singlet (S), host triplet (T h ), and guest triplet (T g ) densities as functions of time, t, are described using [10]:…”

Section: Theorymentioning

confidence: 99%

“…With an adequate understanding of these properties, management of singlet and triplet energy transfer can, for example, lead to high efficiency white organic light emitting diodes (OLEDs) [4], or determine the rate of triplet-triplet (TTA) and/or singlet-triplet annihilation (STA) in fluorescent OLEDs [5][6][7][8][9]. Furthermore, it has been shown that exciton management in organic semiconductor lasers can mitigate tripletinduced losses to result in quasi-continuous wave lasing [10].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Temperature dependence of the exciton dynamics inDCM2:Alq3

2014

Self Cite

View full text Add to dashboard Cite

We study the temperature dependence of the triplet and singlet exciton dynamics in the archetype small molecule fluorescent guest-host system, tris(8-hydroxyquinolinato) aluminum (Alq 3 ) doped with 4-(dicyanomethylene)-2-methyl-6-julolidyl-9-enyl-4H-pyran (DCM2). We develop a comprehensive model of the exciton dynamics, and use it to fit the transient photoluminescence under different pulsed optical pumping in the temperature range of 80 K< T< 295 K. The triplet decay has a significantly different temperature dependence than that of singlets. From 295K to 80K, the triplet-triplet annihilation (TTA) rate decreases by two orders of magnitude, whereas the singlet-triplet annihilation rate decreases by <50% primarily a result of the different energy transfer mechanisms of singlets and triplets. The temperature dependence of TTA rate reveals two regimes separated by a transition at 180K from Marcus to MillerAbrahams transfer. This work deepens our understanding of exciton dynamics and energy transfer in small molecule organic materials.2

show abstract

“…Finally, k hg = 4 × 10 10 s -1 is obtained from Ref. [10]. Figure 2 shows the result of fits that yield N 0 , k ST , and k ISC from the PL transients in Fig.…”

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Theorymentioning

confidence: 99%

“…via a Dexter process). The singlet (S), host triplet (T h ), and guest triplet (T g ) densities as functions of time, t, are described using [10]:…”

Section: Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Temperature dependence of the exciton dynamics inDCM2:Alq3

2014

Self Cite

View full text Add to dashboard Cite

show abstract

An Organic Laser Dye having a Small Singlet‐Triplet Energy Gap Makes the Selection of a Host Material Easier

Karunathilaka

Balijapalli

Senevirathne

et al. 2020

Adv Funct Materials

View full text Add to dashboard Cite

Quenching of singlets by long-lived triplets is a serious issue for lasing from organic laser dyes, especially under long pulse excitation duration. As a strategy to scavenge or manage unnecessary triplets, an organic laser dye is dispersed into a host material having high singlet and low triplet energy levels [a large singlet-triplet energy gap (ΔE ST )]. However, finding such a host material having a triplet scavenging capability is limited. In this study, we synthesized an organic laser dye, 2,6-dicyano-1,1-diphenyl-λ 5 σ 4 -phosphinine (DCNP), having a small ΔE ST of ~0.44 eV, and thus we were able to employ 4-4΄-bis[(N-carbazole)styryl] biphenyl (BSBCz) as a triplet scavenging host, i.e., the triplets formed on DCNP are easily transferred to BSBCz. A 1 wt.%-DCNP-doped BSBCz film was formed on a mixed-order distributed feedback grating, showed lasing with a low threshold value of ~0.86 µJ cm −2 and a FWHM of ~0.5 nm. Because of the suppressed singlet-triplet annihilation, we demonstrated DCNP-based laser devices operating under continuous-wave operation, with a low threshold of 72 W cm −2 and a long laser half-lifetime of ~3 min. Our results This article is protected by copyright. All rights reserved.3 demonstrated a possibility of the wider selection of host materials, easing a material design strategy of fabricating high-performance laser devices in future.Received: ((will be filled in by the editorial staff))Revised: ((will be filled in by the editorial staff)) Published online: ((will be filled in by the editorial staff))

show abstract

Light Amplification and Efficient Electroluminescence from a Solution‐Processable Diketopyrrolopyrrole Derivative via Triplet‐to‐Singlet Upconversion

Shukla

McGregor

Wawrzinek

et al. 2021

Adv Funct Materials

View full text Add to dashboard Cite

Over the years, achieving efficient electroluminescence (EL) while simultaneously having low light amplification thresholds under optical excitation has been the key to progression toward the long‐thought objective of electrically pumped organic lasers. While significant progress in this regard has been made for organic semiconductors emitting in the blue–green region of the visible spectrum, organic laser dyes with low‐energy emission (>600 nm) still suffer from high amplified spontaneous emission (ASE) thresholds and low external quantum efficiencies (EQEs) in devices. Herein, low ASE thresholds and efficient EL are reported from a solution‐processable organic laser dye dithiophenyl diketopyrrolopyrrole (DT‐DPP). The ASE threshold of 4 µJ cm−2 at the wavelength of 620 nm is obtained while making constructive use of triplet excitons by doping DT‐DPP in a green‐emitting host matrix, which exhibits thermally activated delayed fluorescence (TADF). The organic light‐emitting diode fabricated from this system gives a high EQE of 7.9% due to the efficient utilization of triplet excitons. Transient EL studies further show that a high reverse intersystem crossing rate is crucial in achieving lasing under electrical pumping from such TADF‐assisted fluorescent systems.

show abstract

Theory of the perfect lens

Cited by 70 publications

References 51 publications

Temperature dependence of the exciton dynamics inDCM2:Alq3

Temperature dependence of the exciton dynamics inDCM2:Alq3

An Organic Laser Dye having a Small Singlet‐Triplet Energy Gap Makes the Selection of a Host Material Easier

Light Amplification and Efficient Electroluminescence from a Solution‐Processable Diketopyrrolopyrrole Derivative via Triplet‐to‐Singlet Upconversion

Contact Info

Product

Resources

About