In this study, we compared the use of neat bathocuproine (BCP) and BCP:C60 mixed buffer layers in chloroboron subphthalocyanine (SubPc)/C60 bilayer organic photovoltaic (OPV) devices and analyzed their influence on device performance. Replacing the conventional BCP with BCP:C60 enabled manipulating the optical field distribution for optimizing the optical properties of the devices. Estimation of the interfacial barrier indicated that the insertion of the BCP:C60 between the C60 and electrode can effectively reduce the barrier for electrons and enhance electron collection at the electrode. Temperature-dependent measurements of the OPV devices performed to calculate the barrier height at the SubPc/C60 interface suggested that band bending was larger when the BCP:C60 buffer layer was used, reflecting increased exciton dissociation efficiency. In addition, the device lifetime was considerably improved when the BCP:C60 buffer layer was used. The device performance was stabilized after the photodegradation of the active layers, thereby increasing the device lifetime compared with the use of the neat BCP buffer layer. Atomic force microscopy images showed that the neat BCP was easily crystallized and could degrade the cathodic interface, whereas the blend of C60 and BCP suppressed the crystallization of BCP. Therefore, the optimal buffer layer improved both the device performance and the device lifetime.

Visiting a museum is a popular activity in the tourism industry, especially in cultural and learning-based tourism. To help plan museums effectively, this study investigated the underlying motivations and constraints and their impact on the perceived physical environment and visitor satisfaction toward a museum. The results suggest that the physical environment of museums serves as an axial mediator among motivations, constraints and visitor satisfaction. Six essential factors of physical environment are affected by motivations and constraints, further affecting visitor satisfaction in various patterns, in which architectural planning, exhibition, external environment, and entrance are clearly affected by basic motivations and constraints. Under motivations, family education and self-development are the most two profound influences on enhancing visitor satisfaction through the physical environment. Shops and café are worth special attention in meeting motivation of attractiveness, occasion and social interaction. The results could support the planning and design of a satisfactory museum.

No abstract

No abstract

No abstract