有机复合光电导材料及器件研究进展

有机光电导复合材料已经成为当前国际上有机光电材料科学研究的前沿与热点之一。复合化是大幅度提高有机半导体材料光电导性能的有效手段,本文主要从有机光电导材料的复合化角度,综述了新型高效的多种有机复合光电导材料体系的制备及其光电导性能,初步解释了其相应的复合原理和光电导机理,并介绍了其在单层型光电导器件中的研究进展。最后提出了制备高性能有机光电导复合材料及单层型光电导器件的几点建议。     

Cyclic-AMP levels in the lichen Evernia prunastri are modulated by light quantity and quality

Changes in the accumulation of cAMP levels were measured by the isotope dilution assay using protein kinase A in the lichen Evernia prunastri at varying light conditions. cAMP levels decreased following exposure to low irradiance (20 μmol quanta m⁻² s⁻¹, and below the compensation point for photosynthesis) of red light (600–710-nm wave length) and increased by 50% after far-red light illumination (15 μmol quanta m⁻² s⁻¹, 710–800-nm wavelength). Far-red partially reverted the effect of red light when the former was supplied after the latter. cAMP increased to its maximum level under high irradiance supplied by a non-photomorphogenic yellow light source (400 μmol quanta m⁻² s⁻¹, reaching photosynthetic saturation). The addition of small quantities of red and far-red light, however, had profound restricting effects on cAMP accumulation. The addition of inhibitors of electron transport chains did not promote any significant change in cAMP levels in any of the treatments, indicating that cAMP accumulation could not depend on ATP synthesis. We propose that the response of cAMP accumulation at low irradiance comprises the activation of a morphogenic pathway through a red/far-red photoreceptor. In addition, at high irradiance the response would occur most likely through photosystems II and I acting as sensors of light quantity, that can be strongly modified by the red/far-red photomorphogenic system. Thus, cAMP would be involved in sensing the overall light environment.