TY - JOUR
T1 - Green/Yellow solid-state lighting via radiative and nonradiative energy transfer involving colloidal semiconductor nanocrystals
AU - Nizamoglu, Sedat
AU - Sari, Emre
AU - Baek, Jong Hyeob
AU - Lee, In Hwan
AU - Volkan Demir, Hilmi
N1 - Funding Information:
Manuscript received December 1, 2008; revised December 24, 2008 and January 20, 2009. Current version published August 5, 2009. This work was supported in part by the Turkish National Academy of Sciences Distinguished Young Scientist Award Program (TUBA GEBIP), in part by the European Science Foundation European Young Investigator Award Program (ESF-EURYI) under Grant EU MOON 02139, and in part by TUBITAK EEEAG under Grant 107E297, Grant 104E114, Grant 106E020, Grant 107E080, Grant 105E065, and Grant 105E066.
PY - 2009
Y1 - 2009
N2 - LEDs made of InxGa1-xN and (AlxGa 1-x1-yInyP suffer from significantly reduced quantum efficiency and luminous efficiency in the green/yellow spectral ranges. To address these problems, we present the design, growth, fabrication, hybridization, and characterization of proof-of-concept green/yellow hybrid LEDs that utilize radiative and nonradiative [Förster resonance energy transfer (FRET)] energy transfers in their colloidal semiconductor nanocrystals (NCs) integrated on near-UV LEDs. In our first NC-LED, we realize a color-converted LED that incorporate green-emitting CdSe/ZnS core/shell NCs (λ PL = 548 nm}) on near-UV InGaN/GaN LEDs (λEL = 379 nm). In our second NC-LED, we implement a color-converted FRET-enhanced LED. For that, we hybridize a custom-design assembly of cyan- and green-emitting CdSe/ZnS core/shell NCs (λPL= 490 and 548 nm) on near-UV LEDs. Using a proper mixture of differently sized NCs, we obtain a quantum efficiency enhancement of 9% by recycling trapped excitons via FRET. With FRET-NC-LEDs, we show that it is possible to obtain a luminous efficacy of 425 lm/W opt and a luminous efficiency of 94 lm/W, using near-UV LEDs with a 40 external quantum efficiency. Finally, we investigate FRET-converted light-emitting structures that use nonradiative energy transfer directly from epitaxial quantum wells to colloidal NCs. These proof-of-concept demonstrations show that FRET-based NC-LEDs hold promise for efficient solid-state lighting in green/yellow.
AB - LEDs made of InxGa1-xN and (AlxGa 1-x1-yInyP suffer from significantly reduced quantum efficiency and luminous efficiency in the green/yellow spectral ranges. To address these problems, we present the design, growth, fabrication, hybridization, and characterization of proof-of-concept green/yellow hybrid LEDs that utilize radiative and nonradiative [Förster resonance energy transfer (FRET)] energy transfers in their colloidal semiconductor nanocrystals (NCs) integrated on near-UV LEDs. In our first NC-LED, we realize a color-converted LED that incorporate green-emitting CdSe/ZnS core/shell NCs (λ PL = 548 nm}) on near-UV InGaN/GaN LEDs (λEL = 379 nm). In our second NC-LED, we implement a color-converted FRET-enhanced LED. For that, we hybridize a custom-design assembly of cyan- and green-emitting CdSe/ZnS core/shell NCs (λPL= 490 and 548 nm) on near-UV LEDs. Using a proper mixture of differently sized NCs, we obtain a quantum efficiency enhancement of 9% by recycling trapped excitons via FRET. With FRET-NC-LEDs, we show that it is possible to obtain a luminous efficacy of 425 lm/W opt and a luminous efficiency of 94 lm/W, using near-UV LEDs with a 40 external quantum efficiency. Finally, we investigate FRET-converted light-emitting structures that use nonradiative energy transfer directly from epitaxial quantum wells to colloidal NCs. These proof-of-concept demonstrations show that FRET-based NC-LEDs hold promise for efficient solid-state lighting in green/yellow.
KW - F̈orster resonance energy transfer (FRET)
KW - Green/yellow
KW - InGaN/GaN
KW - LEDs
KW - Nanocrystals (NCs)
KW - Nonradiative energy transfer
UR - http://www.scopus.com/inward/record.url?scp=70349319688&partnerID=8YFLogxK
U2 - 10.1109/JSTQE.2009.2015680
DO - 10.1109/JSTQE.2009.2015680
M3 - Article
AN - SCOPUS:70349319688
VL - 15
SP - 1163
EP - 1170
JO - IEEE Journal on Selected Topics in Quantum Electronics
JF - IEEE Journal on Selected Topics in Quantum Electronics
SN - 1077-260X
IS - 4
M1 - 5170075
ER -