TY - JOUR
T1 - A Comparative Study of the Semiconductor Behavior of Organic Thin Films
T2 - TCNQ-Doped Cobalt Phthalocyanine and Cobalt Octaethylporphyrin
AU - Sánchez-Vergara, María Elena
AU - Rios, Citlalli
AU - Jiménez-Sandoval, Omar
AU - Salcedo, Roberto
N1 - Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020/12/1
Y1 - 2020/12/1
N2 - The structure formed by cobalt phthalocyanine (CoPc) and cobalt octaethylporphyrin (CoOEP) with electron-acceptor tetracyano-π-quinodimethane (TCNQ), was studied by Density Functional Theory (DFT) methods. According to theoretical calculations, both cobalt systems can establish dispersion forces related to TCNQ and also in both cases the link between them is built by means of hydrogen bonds. Based on the results of these DFT calculations, we developed experimental work: the organic semiconductors were doped, and the thermal evaporation technique was used to prepare semiconductor thin films of such compounds. The structure of the films was studied by FTIR and Raman spectroscopy. The optical properties of the CoPc-TCNQ and CoOEP-TCNQ films were investigated by means of UV-Vis measurements. The results obtained were used to estimate the type of transitions and the optical bandgap. The results were compared to the previously calculated theoretical bandgap. The CoOEP-TCNQ film presented the smallest theoretical and experimental bandgap. Finally, the electrical properties of the organic semiconductors were evaluated from a PET (polyethylene terephthalate)/indium tin oxide (ITO)/cobalt macrocycle-TCNQ/silver (Ag) device we prepared. The CoOEP-TCNQ-based device showed an ohmic behavior. The device manufactured from CoPc-TCNQ also showed an ohmic behavior at low voltages, but significantly changed to SCLC (space-charge limited conductivity) at high voltage values.
AB - The structure formed by cobalt phthalocyanine (CoPc) and cobalt octaethylporphyrin (CoOEP) with electron-acceptor tetracyano-π-quinodimethane (TCNQ), was studied by Density Functional Theory (DFT) methods. According to theoretical calculations, both cobalt systems can establish dispersion forces related to TCNQ and also in both cases the link between them is built by means of hydrogen bonds. Based on the results of these DFT calculations, we developed experimental work: the organic semiconductors were doped, and the thermal evaporation technique was used to prepare semiconductor thin films of such compounds. The structure of the films was studied by FTIR and Raman spectroscopy. The optical properties of the CoPc-TCNQ and CoOEP-TCNQ films were investigated by means of UV-Vis measurements. The results obtained were used to estimate the type of transitions and the optical bandgap. The results were compared to the previously calculated theoretical bandgap. The CoOEP-TCNQ film presented the smallest theoretical and experimental bandgap. Finally, the electrical properties of the organic semiconductors were evaluated from a PET (polyethylene terephthalate)/indium tin oxide (ITO)/cobalt macrocycle-TCNQ/silver (Ag) device we prepared. The CoOEP-TCNQ-based device showed an ohmic behavior. The device manufactured from CoPc-TCNQ also showed an ohmic behavior at low voltages, but significantly changed to SCLC (space-charge limited conductivity) at high voltage values.
KW - DFT calculations
KW - doped semiconductor
KW - electrical properties
KW - flexible film
KW - optical properties
UR - http://www.scopus.com/inward/record.url?scp=85098476033&partnerID=8YFLogxK
U2 - 10.3390/MOLECULES25245800
DO - 10.3390/MOLECULES25245800
M3 - Artículo
C2 - 33316924
AN - SCOPUS:85098476033
SN - 1420-3049
VL - 25
JO - Molecules
JF - Molecules
IS - 24
M1 - 5800
ER -