Optical second harmonic generation spectra in vacuum‐deposited thin films of various phthalocyanines

Extracting the Density of States of Copper Phthalocyanine at the SiO2 Interface with Electronic Sum Frequency Generation

“…Turning our focus to the high-energy band that appears in the PPP spectrum, we find that it roughly falls into resonance with the Q CT peak observed in CuPc’s linear absorption spectrum. As such, we assign this band to Q CT in accord with prior SHG work performed on CuPc films. , Interestingly, the Q CT resonance also appears in the SSP spectrum but displays lower amplitude and is noticeably blue-shifted with a peak near λ WL = 535 nm. As we discuss below, we believe this amplitude change is in part related to the orientation of interfacial CuPc molecules.…”

“…In addition, ESFG lineshapes are found to be strongly dependent on film thickness. Prior studies of CuPc films using a related even-order nonlinear spectroscopy, second harmonic generation (SHG), observed a similar dependence of the SHG signal on film thickness. − While these studies attributed this result to electric quadrupolar coupling of the SHG fields to the bulk of their sample films, a process permitted in centrosymmetric media, − these studies neglected to consider that optically thin CuPc films necessarily have two SHG active surfaces. As such, dipolar fields emitted by these surfaces are expected to interfere with one another and could explain the experimentally observed thickness trend.…”

Role of Structural Factors in the Nonlinear Optical Properties of Phthalocyanines and Related Compounds

“…A number of studies have also been performed on macroscopic Pc systems. As a first remark, one should mention that Hoshi and co-workers found fairly strong SHG from thin films [69][70][71][72] and discotic phases 73 of metal-free phthalocyanine and some centrosymmetric metallic complexes despite their centrosymmetry. After the analysis of different possible mechanisms, the authors considered that an electrical quadrupole transition can rationalize the observed phenomenon.…”

Voltammetry and Spectroelectrochemical Behavior of a Novel Octapropylporphyrazinato Lead(II) Complex

“…It has been found that metal ions could be integrated to the macrocyclic core of the porphyrazines more effectively than that of Pc 6,11 due to the relatively large radius as compared to the phthalocyanine core. The molecule containing heavy metals such as Sn and Pb processes enhancing optical limiting capability with relative instability. , As a p-type semiconducting material, lead(II) phthalocyanine (PbPc) was reported to be sensitive to many gases, such as NO 2 , NH 3 , Cl 2 , and H 2 . The position of the lead atom in the tetrapyrolic macrocycle skeleton differs from the position of the other transition metal atoms in the core of the complexes.…”