Photovoltaic Effect in Phthalocyanine-Based Organic Solar Cells: 3. Exciton Trapping Followed by Charge Carrier Generation

• Published in: High energy chemistry Vol. 55; no. 1; pp. 1 - 10
• Main Authors: Benderskii, V. A., Kim, I. P.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 2021; Springer Nature B.V
• Subjects: Carrier density; Chemistry; Chemistry and Materials Science; Current carriers; Excitons; Impurities; Luminous intensity; Photonics; Photovoltaic cells; Photovoltaic effect; Physical Chemistry; Rate constants; Solar cells; phthalocyanines; dopants; excitons; charge carrier trapping and recombination; quasi-Fermi levels
• ISSN: 0018-1439; 1608-3148
• DOI: 10.1134/S0018143921010045

A kinetic model Nd(Na) of the photovoltaic effect in phthalocyanine (Pc) layers doped with a donor D (acceptor A) in concentration forming one impurity level with energy
E
D
(
E
A
) in the band gap is proposed. The photovoltaic effect is due to the transfer of energy of molecular excitons
S
1
to neutral
A
(
D
) and ionized
A
−
(
D
+
) impurities followed by the formation of electrons and holes:
S
1
+
D
(
A
) →
D
+
(
A
−
) +
e
−
(
h
+
) and
S
1
+
D
+
(
A
−
) →
D
(
A
) +
h
+
(
e
−
). The quasi-stationary concentrations of charge carriers, the population of ionized impurity levels, and the energies of quasi-Fermi levels have been found as functions of light intensity and
E
d
,
N
d
(
E
a
,
N
a
). The values of rate constants that ensure the maximum quantum yield of conversion are discussed.