[en] The electrical characteristics of organic light-emitting devices are calculated for the dc and ac regimes by numerically solving the basic semiconductor equations under steady-state and small-signal conditions. For a given structure, the dc and ac electric potential and electric field, the electron and hole concentrations, as well as the different components of the current density are obtained as function of the one-dimensional spatial coordinate. This approach allows a detailed microscopic description of the dependencies of these quantities on the applied steady-state voltage V0 and the frequency of the modulating voltage. The final output consists in the frequency-dependent complex admittance and impedance of the device, the real and imaginary parts of which are the experimentally-available data. As a typical example, we show the results for a two-layer structure where α-NPD is the hole-transporting material and Alq3 the electron-transporting material. The anode is made of ITO and Al/LiF composes the cathode. The admittance and impedance curves, yielded by the numerical simulation as functions of the modulation frequency, are fitted by an equivalent electrical circuit, the elements of which are resistances and capacitances. The number of com- ponents depends on the structure composition and on the applied steady-state voltage. We show that each element can be associated with a particular region of the device. This allows to correlate the dependence of each feature of the admittance and impedance curves with one or several parameters describing the ma- terial system. Such an analysis can be useful for the inverse approach, where, starting from measurements of the electrical ac characteristics, the aim is to get information on the microscopic mechanisms which contribute to the electrical conduction of the device.
Disciplines :
Physics
Author, co-author :
Nguyen, Ngoc Duy ; Université de Liège - ULiège > Département de physique > Physique des solides, interfaces et nanostructures
Schmeits, Marcel; Université de Liège - ULiège > Département de physique
Language :
English
Title :
Numerical simulation of impedance and admittance of OLEDs
Publication date :
2006
Journal title :
Physica Status Solidi A. Applications and Materials Science
scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.
Bibliography
W. Bruiting, S. Berieb, and A. G. MÜckl, Org. Electron. 2, l (2001).
D. M. Taylor and H. L. Gomes, J. Phys. D 28, 2554 (1995).
I. H. Campbell, D. L. Smith, and J. P. Ferraris, Appl. Phys. Lett. 66, 3030 (1995).
M. G. Harrison, J. GrÜner, and G. C. W. Spencer, Synth. Met. 76, 71 (1996).
M. Meier, S. Karg, and W. Riess, J. Appl. Phys. 82, 1961 (1997).
J. Scherbel, P. H. Nguyen, G. Paasch, W. Brütting, and M. Schwoerer, J. Appl. Phys. 83, 5045 (1998).
C. Jonda and A. B. R. Mayer, Chem. Mater. 11, 2429 (1999).
S. H. Kim, K. H. Choi, H.-M. Lee, D. H. Hwang, L. M. Do, H. Y. Chu, and T. Zyung, J. Appl. Phys. 87, 882 (2000).
H. W. Rhee, K. S. Chin, S. Y. Oh, and J.-W. Choi, Thin Solid Films 363, 236 (2000).
R. Ono, M. Kiy, I. Biaggio, and P. Günter, Mater. Sci. Eng. B 85, 144 (2001).
J. Drechsel, M. Pfeiffer, X. Zhou, A. Nollau, and K. Leo, Synth. Met. 127, 201 (2002).
S. H. Kim, J. W. Jang, K. W. Lee, C. E. Lee, and S. W. Kim, Solid State Commun. 128, 143 (2003).
S. Grecu, M. Bronner, A. Opitz and W. Brütting, Synth. Met. 146, 359 (2004).
A. el Hakim, I. Thurzo, T. U. Kämpen, and D. R. T. Zahn, Appl. Surf. Sci. 234, 149 (2004).
S. H. Kim, S. C. Lim, J. H. Lee, and T. Zyung, Curr. Appl. Phys. 5, 35 (2005).
A. B. Walker, A. Kambili, and S. J. Martin, J. Phys.: Condens. Mater. 14, 9825 (2002).
S. Selberherr, Analysis and Simulation of Semiconductor Devices (Wiley, New York, 1981).
J. Shen and J. Yang, J. Appl. Phys. 83, 7706 (1998).
E. Tutis, M. N. Bussac, B. Masenelli, M. Carrard, and L. Zuppiroli, J. Appl. Phys. 89, 430 (2001).
C. D. J. Blades and A. B. Walker, Synth. Met. 111/112, 335 (2000).
B. Ruhstaller, T. Beierlein, H. Riel, S. Karg, J. Campbell Scott, and W. Riess, IEEE J. Sel. Top. 9, 723 (2003).
G. Paasch, A. Nesterov, and S. Scheinert, Synth. Met. 139, 425 (2003).
N. Tessler, D. J. Pinner, and R. H. Friend, Synth. Met. 111/112, 269 (2000).
D. J. Pinner, R. H. Friend, and N. Tessler, J. Appl. Phys. 86, 5116 (1999).
M. Schmeits, N. D. Nguyen, and M. Germain, J. Appl. Phys. 89, 1890 (2001).
J. C. Scott and G. G. Malliaras, Chem. Phys. Lett. 299, 115 (1999).
L. S. Hung, C. W. Tang, and M. G. Mason, Appl. Phys. Lett. 70, 152 (1997).
G. Parthasarathy, C. Shen, A. Kahn, and S. R. Forrest, J. Appl. Phys. 89, 4986 (2001).
M. Sakhaf and M. Schmeits, J. Appl. Phys. 80, 6839 (1996).
Y. Roichman and N. Tessler, Appl. Phys. Lett. 80, 1948 (2002).
M. Schmeits, J. Appl. Phys. 80, 941 (1996).
Y. Roichman, Y. Preezant, and N. Tessler, phys. stat. sol. (a) 201, 1246 (2004).
This website uses cookies to improve user experience. Read more
Save & Close
Accept all
Decline all
Show detailsHide details
Cookie declaration
About cookies
Strictly necessary
Performance
Strictly necessary cookies allow core website functionality such as user login and account management. The website cannot be used properly without strictly necessary cookies.
This cookie is used by Cookie-Script.com service to remember visitor cookie consent preferences. It is necessary for Cookie-Script.com cookie banner to work properly.
Performance cookies are used to see how visitors use the website, eg. analytics cookies. Those cookies cannot be used to directly identify a certain visitor.
Used to store the attribution information, the referrer initially used to visit the website
Cookies are small text files that are placed on your computer by websites that you visit. Websites use cookies to help users navigate efficiently and perform certain functions. Cookies that are required for the website to operate properly are allowed to be set without your permission. All other cookies need to be approved before they can be set in the browser.
You can change your consent to cookie usage at any time on our Privacy Policy page.