TY - JOUR
T1 - Effects of additives in polymer thick film-organic light emitting diodes (PTF-OLED)
AU - LEUNG, Louis M L
AU - Kwong, C. F.
AU - SO, Shu Kong
N1 - Funding Information:
This work is supported by a research grant from the research grant council of the Hong Kong SAR Government (grant number: HKBU 2057/98E) and a faculty research grant from the university (FRG/00-01/II-41).
PY - 2002/9
Y1 - 2002/9
N2 - The optimum composition and film thickness determined for a single-layer organic light emitting diodes (120-150cd/m2 at 30mA/cm2) has been determined in one of our previous publication [Display 21 (2001) 199]. In this following study, a series of additives was included in the original composition for the purposes of color tuning, enhancement of the device efficiency as well as the stability of the polymer thick film-organic light emitting diodes (PTF-OLED). The additives attempted including three dyes (rubrene, perylene and DCM), three sensitizers (naphthalene, anthracene and p-terphenyl), several stabilizers (antioxidant and photo-stabilizer) and a number of organic soluble salts known as phase transfer catalyst. Rubrene was found being able to improve the OLED efficiency by 3-fold and its durability by at least 60 times at a concentration of 5-10pph (in part per hundred of Alq3 replaced). The color of the OLED can also be tuned according to the additional dye used. The sensitizer naphtahlene can also improved the efficiency of the OLED by 2-fold while the effect of the other additives was less significant. In addition, the lowering of the turn-on voltage and thus a higher current efficiency resulted by the addition of a charge injection layer (lithium fluoride or calcium fluoride) in between the cathode and the organic layer. The performance of the doped PTF-OLED is within an order of magnitude compared to a heterojunction small molecule-based OLED.
AB - The optimum composition and film thickness determined for a single-layer organic light emitting diodes (120-150cd/m2 at 30mA/cm2) has been determined in one of our previous publication [Display 21 (2001) 199]. In this following study, a series of additives was included in the original composition for the purposes of color tuning, enhancement of the device efficiency as well as the stability of the polymer thick film-organic light emitting diodes (PTF-OLED). The additives attempted including three dyes (rubrene, perylene and DCM), three sensitizers (naphthalene, anthracene and p-terphenyl), several stabilizers (antioxidant and photo-stabilizer) and a number of organic soluble salts known as phase transfer catalyst. Rubrene was found being able to improve the OLED efficiency by 3-fold and its durability by at least 60 times at a concentration of 5-10pph (in part per hundred of Alq3 replaced). The color of the OLED can also be tuned according to the additional dye used. The sensitizer naphtahlene can also improved the efficiency of the OLED by 2-fold while the effect of the other additives was less significant. In addition, the lowering of the turn-on voltage and thus a higher current efficiency resulted by the addition of a charge injection layer (lithium fluoride or calcium fluoride) in between the cathode and the organic layer. The performance of the doped PTF-OLED is within an order of magnitude compared to a heterojunction small molecule-based OLED.
KW - Additives
KW - Organic light emitting diodes
KW - Polymer thick film inks
KW - Sensitizers
UR - http://www.scopus.com/inward/record.url?scp=0036753475&partnerID=8YFLogxK
U2 - 10.1016/S0141-9382(02)00035-5
DO - 10.1016/S0141-9382(02)00035-5
M3 - Article
AN - SCOPUS:0036753475
SN - 0141-9382
VL - 23
SP - 171
EP - 175
JO - Displays
JF - Displays
IS - 4
ER -