Operational stability of electrophosphorescent devices containing p and n doped transport layers

D'Andrade, Brian W.; Forrest, Stephen R.; Chwang, Anna B.
November 2003
Applied Physics Letters;11/10/2003, Vol. 83 Issue 19, p3858
Academic Journal
The operational stability of low-operating voltage p-i-n electrophosphorescent devices containing fac-tris(2-phenylpyridine) iridium as the emissive dopant is investigated. In these devices, Li-doped 4,7-diphenyl-1,10-phenanthroline (BPhen) served as an n-type electron transport layer, or as an undoped hole blocking layer (HBL), and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane doped 4,4[sup ′],4[sup ″]-tris(3-methylphenylphenylamino) triphenylamine served as a p-type hole transport layer. The glass transition temperature of BPhen can be increased by the addition of aluminum(III)bis(2-methyl-8-quinolinato)4-phenylphenolate (BAlq), resulting in improved morphological stability, thereby reducing device degradation. When thermally stable BAlq was used as a HBL in both p-i-n and undoped devices, the extrapolated operational lifetime (normalized to an initial luminance of 100 cd/m[sup 2]) of the p-i-n and undoped devices are 18 000 and 60 000 h, respectively, indicating that the presence of p and n dopants can accelerate device degradation. © 2003 American Institute of Physics.


Related Articles

  • Effect of plasticization of dye doped polymer on second-order optical nonlinearity induced by electric field. Sugihara, Takashi; Fujii, Kouji; Haga, Hiroshi; Yamamoto, Sadahiko // Applied Physics Letters;11/11/1996, Vol. 69 Issue 20, p2971 

    The nonlinear molecules dispersed in the polymer with low glass transition temperature (Tg) can be easily reoriented. The plasticizer is utilized in order to lower the Tg of the polymer matrix. We measured the frequency responses of second-harmonic generation in a dye doped plasticized polymer...

  • Cooperative energy transfer in Yb[sup 3+]-Tb[sup 3+] codoped silica sol-gel glasses. Martín, I. R.; Yanes, A. C.; Méndez-Ramos, J.; Torres, M. E.; Rodríguez, V. D. // Journal of Applied Physics;3/1/2001, Vol. 89 Issue 5, p2520 

    Optical properties of Yb[sup 3+]-Tb[sup 3+] codoped silica sol-gel samples have been studied after the gel to glass transition. Different upconversion emissions have been observed under near infrared excitation at about 1 μm. The Tb[sup 3+] ions are excited by means of energy transfer...

  • Kinetics of nonisothermal crystallization in Sn10Sb20− xBi xSe70 glassy semiconductors. Ahmad, M.; Kumar, P.; Suri, N.; Kumar, J.; Thangaraj, R. // Applied Physics A: Materials Science & Processing;Mar2009, Vol. 94 Issue 4, p933 

    The crystallization kinetics of Sn10Sb20− xBi x Se70 ( x=0,2,4,6,8) chalcogenide system has been studied. Crystallization studies using differential scanning calorimetry under nonisothermal conditions with different heating rates are reported. The glass transition temperature is found to...

  • Thermal and optical analysis of Te-substituted Sn–Sb–Se chalcogenide semiconductors. Chander, Ravi; Thangaraj, R. // Applied Physics A: Materials Science & Processing;Apr2010, Vol. 99 Issue 1, p181 

    Bulk amorphous samples of Te-substituted Sn10Sb20Se70− XTe X (0≤ X≤12) were prepared using a melt quenching technique. Calorimetric studies of the samples were performed using differential scanning calorimetry (DSC) and the glass transition temperature and crystallization...

  • Electronic structure and the glass transition in pnictide and chalcogenide semiconductor alloys. II. The intrinsic electronic midgap states. Zhugayevych, Andriy; Lubchenko, Vassiliy // Journal of Chemical Physics;12/21/2010, Vol. 133 Issue 23, p234504 

    We propose a structural model that treats in a unified fashion both the atomic motions and electronic excitations in quenched melts of pnictide and chalcogenide semiconductors. In Part I [A. Zhugayevych and V. Lubchenko, J. Chem. Phys. 133, 234503 (2010)], we argued these quenched melts...

  • Anomalous thermal effects in crystallization of hydrogenated amorphous alloys of the TiNi-TiCu system. Spivak, L. V.; Shelyakov, A. V. // Technical Physics Letters;Dec2009, Vol. 35 Issue 12, p1137 

    Several anomalous effects not reported previously for the interaction of hydrogen with amorphous alloys of the TiNi-TiCu system have been observed, including (i) the passage from one-to multistage mechanism of the transition from the amorphous to crystalline state in hydrogenated alloys, (ii) a...

  • Glass-forming ability and fragility parameter of amorphous Fe67Co9.5Nd3Dy0.5B20. Biswas, K.; Venkataraman, S.; Zhang, W. Y.; Ram, S.; Eckert, J. // Journal of Applied Physics;7/15/2006, Vol. 100 Issue 2, p023501 

    The glass-forming ability of amorphous Fe67Co9.5Nd3Dy0.5B20 has been analyzed in terms of the width of the supercooled liquid region, the reduced glass transition temperature, the recently proposed parameter γ, the Hruby parameter [Czech. J. Phys., Sect. B 22, 1187 (1972)] Kgl, and the...

  • Spirocyclic Aromatic Hydrocarbons (SAHs) and their Synthetic Methodologies. Ling-Hai Xie; Jing Liang; Juan Song; Cheng-Rong Yin; Wei Huang // Current Organic Chemistry;Nov2010, Vol. 14 Issue 18, p2169 

    No abstract available.

  • Materials Communications: Plastic instability in amorphous selenium near its glass transition temperature. Caijun Su; LaManna, James A.; Yanfei Gao; Oliver, Warren C.; Pharr, George M. // Journal of Materials Research;Jun2010, Vol. 25 Issue 6, p8 

    The deformation behavior of amorphous selenium near its glass transition temperature (31 °C) has been investigated by uniaxial compression and nanoindentation creep tests. Cylindrical specimens compressed at high temperatures and low strain rates deform stably into barrel-like shapes, while...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics