TY - JOUR
T1 - Tetraoctylammonium Bromide Interlayer between NiLiOx and Perovskite for Light-Emitting Diodes
AU - Vo, Van Khoe
AU - Bae, Sung Hoon
AU - Dang, Thi Huong Thao
AU - Phung, Dinh Hoat
AU - Kim, Juhan
AU - Lee, Seungwon
AU - Lee, Nayoon
AU - Lim, Hyo Jun
AU - Kim, Ki Hee
AU - Lee, Joon Hyung
AU - Heo, Young Woo
N1 - Publisher Copyright:
© 2024 American Chemical Society.
PY - 2024/11/20
Y1 - 2024/11/20
N2 - Physical vapor deposition is a favorable technique for fabricating light-emitting diodes (LEDs) due to its scalability and reproducibility. However, the performances of LEDs fabricated via this method are worse than those prepared via solution processing owing to the generation of high defect densities. In this study, we introduce a layer of tetraoctylammonium bromide (TOABr), an interfacial-modification compound containing four long octyl chains that are symmetrically arranged around an N atom, to reduce nonradiative recombination and trap densities in CsPbBr3. We examined the impacts of adding TOABr on perovskite thin films deposited on hole injection layers made of Li-doped NiOx and poly(3,4-ethylenedioxythiophene)/polystyrenesulfonate. Our investigations reveal that TOABr addition slightly increases crystallinity, dramatically increases photoluminescence, and achieves the preferred orientation in the perovskite films. Additionally, the interfacial layer passivates defects and improves charge balance in the device, thereby enhancing performance. Consequently, perovskite LEDs with a TOABr layer exhibit a lower turn-on voltage of 3 V than their pristine counterparts, achieving a maximum luminance of 11,133 cd m-2 and an external quantum efficiency of 1.24%, whereas the pristine perovskite LEDs achieve an EQE of 0.015%. The approach proposed in this study can be used to fabricate efficient vacuum-thermal-evaporated perovskite LEDs.
AB - Physical vapor deposition is a favorable technique for fabricating light-emitting diodes (LEDs) due to its scalability and reproducibility. However, the performances of LEDs fabricated via this method are worse than those prepared via solution processing owing to the generation of high defect densities. In this study, we introduce a layer of tetraoctylammonium bromide (TOABr), an interfacial-modification compound containing four long octyl chains that are symmetrically arranged around an N atom, to reduce nonradiative recombination and trap densities in CsPbBr3. We examined the impacts of adding TOABr on perovskite thin films deposited on hole injection layers made of Li-doped NiOx and poly(3,4-ethylenedioxythiophene)/polystyrenesulfonate. Our investigations reveal that TOABr addition slightly increases crystallinity, dramatically increases photoluminescence, and achieves the preferred orientation in the perovskite films. Additionally, the interfacial layer passivates defects and improves charge balance in the device, thereby enhancing performance. Consequently, perovskite LEDs with a TOABr layer exhibit a lower turn-on voltage of 3 V than their pristine counterparts, achieving a maximum luminance of 11,133 cd m-2 and an external quantum efficiency of 1.24%, whereas the pristine perovskite LEDs achieve an EQE of 0.015%. The approach proposed in this study can be used to fabricate efficient vacuum-thermal-evaporated perovskite LEDs.
KW - CsPbBr
KW - inorganic perovskite
KW - interlayer
KW - light-emitting diodes
KW - perovskite
KW - vacuum thermal evaporation
UR - http://www.scopus.com/inward/record.url?scp=85209756878&partnerID=8YFLogxK
U2 - 10.1021/acsami.4c13287
DO - 10.1021/acsami.4c13287
M3 - Article
C2 - 39530385
AN - SCOPUS:85209756878
SN - 1944-8244
VL - 16
SP - 64210
EP - 64221
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 46
ER -