Scientists / Open questions

Chihaya Adachi

Organic optoelectronics; luminescent materials

15 questions

A quantitative, predictive account of thermally activated delayed fluorescence in carbazolyl-dicyanobenzene emitters: singlet–triplet spin mixing, low-temperature decay heterogeneity, kinetic-model validity, and structure–efficiency relationships
Microscopic mechanisms of unreacted PbI2-mediated degradation in perovskite solar cells: origin of enhanced ion-migration hysteresis, spatial distribution of metallic lead, and composition dependence of precursor excess
Suppressing external quantum efficiency roll-off at high current density in thermally activated delayed fluorescence organic light-emitting diodes
Quantitative microscopic mechanism of "partial uphill" electron injection from weak molecular donors into single-walled carbon nanotube films and a predictive basis for the HOMO-threshold rule for n-type thermoelectric conversion
Exciplex-based reverse-intersystem-crossing (TADF) OLEDs: raising efficiency through materials design, triplet confinement, and the unresolved energetic inhomogeneity of exciplex charge-transfer states
Commercial-grade stability for pure-blue hyperfluorescence OLEDs: narrowband, efficient, long-lived devices and the underlying exciton and charge-management science
Generality and operational-stability limits of the multi-donor charge-resonance design for fast spin-flip charge-transfer emitters in organic light-emitting diodes
Operational color stability and lifetime of single-dopant monomer-aggregate white electrophosphorescent OLEDs
Triplet exciton physics and the robustness of room-temperature continuous-wave lasing in quasi-2D lead-halide perovskite films
Loss-free exciton funneling and a quantitative efficiency budget in TADF assistant-dopant (hyperfluorescent) OLEDs with fluorescent emitters
Mechanism of the electroluminescence-specific 'hidden' delayed-fluorescence channel in heptazine-based OLED emitters: state ordering, temperature dependence, and EL-relevant screening criteria
From empirical selection rules to predictive design: efficiency mechanisms, degradation pathways, and molecular design principles for bright, operationally stable blue organic electroluminescent devices
Predictive design rules, efficiency roll-off, and operational lifetime of efficient pure-blue thermally activated delayed fluorescence OLED emitters
Translating unity internal quantum efficiency of the purely organic TADF emitter DACT-II into practical OLED performance: out-coupling-limited external efficiency at high luminance, amorphous-state singlet-triplet gap disorder, and operational lifetime
Harvesting triplet excitons in near-infrared TADF emitters for continuous-wave and electrically pumped organic light amplification

Back to open problems

A quantitative, predictive account of thermally activated delayed fluorescence in carbazolyl-dicyanobenzene emitters: singlet–triplet spin mixing, low-temperature decay heterogeneity, kinetic-model validity, and structure–efficiency relationships

Microscopic mechanisms of unreacted PbI2-mediated degradation in perovskite solar cells: origin of enhanced ion-migration hysteresis, spatial distribution of metallic lead, and composition dependence of precursor excess

Suppressing external quantum efficiency roll-off at high current density in thermally activated delayed fluorescence organic light-emitting diodes

Quantitative microscopic mechanism of "partial uphill" electron injection from weak molecular donors into single-walled carbon nanotube films and a predictive basis for the HOMO-threshold rule for n-type thermoelectric conversion

Exciplex-based reverse-intersystem-crossing (TADF) OLEDs: raising efficiency through materials design, triplet confinement, and the unresolved energetic inhomogeneity of exciplex charge-transfer states

Commercial-grade stability for pure-blue hyperfluorescence OLEDs: narrowband, efficient, long-lived devices and the underlying exciton and charge-management science

Generality and operational-stability limits of the multi-donor charge-resonance design for fast spin-flip charge-transfer emitters in organic light-emitting diodes

Operational color stability and lifetime of single-dopant monomer-aggregate white electrophosphorescent OLEDs

Triplet exciton physics and the robustness of room-temperature continuous-wave lasing in quasi-2D lead-halide perovskite films

Loss-free exciton funneling and a quantitative efficiency budget in TADF assistant-dopant (hyperfluorescent) OLEDs with fluorescent emitters

Mechanism of the electroluminescence-specific 'hidden' delayed-fluorescence channel in heptazine-based OLED emitters: state ordering, temperature dependence, and EL-relevant screening criteria

From empirical selection rules to predictive design: efficiency mechanisms, degradation pathways, and molecular design principles for bright, operationally stable blue organic electroluminescent devices

Predictive design rules, efficiency roll-off, and operational lifetime of efficient pure-blue thermally activated delayed fluorescence OLED emitters

Translating unity internal quantum efficiency of the purely organic TADF emitter DACT-II into practical OLED performance: out-coupling-limited external efficiency at high luminance, amorphous-state singlet-triplet gap disorder, and operational lifetime

Harvesting triplet excitons in near-infrared TADF emitters for continuous-wave and electrically pumped organic light amplification