Subgap absorption in conjugated polymers

Conference · Tue Jan 01 00:00:00 EST 1991

OSTI ID:5883862

Sinclair, M; Seager, C H ^[1]; McBranch, D; Heeger, A J ^[2]; Baker, G L ^[3]

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1. Sandia National Labs., Albuquerque, NM (USA)
2. California Univ., Santa Barbara, CA (USA)
3. Bell Communications Research, Inc., Red Bank, NJ (USA)

Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of transparent'' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination. 11 refs., 4 figs.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5883862
• Report Number(s): SAND-90-3023C; CONF-910406--10; ON: DE91012655
• Conference Information: Spring meeting of the Materials Research Society (MRS), Anaheim, CA (USA), 29 Apr - 3 May 1991
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ABSORPTION
ACETYLENE
ALKYNES
HYDROCARBONS
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
POLYMERS
SPECTROSCOPY