The present invention provides novel triazatruxene derivatives that are useful as hole transport materials (HTM), particularly, in optoelectronic devices. The utility of the novel compounds was confirmed in solid-state, sensitized solar cells based on organic-inorganic perovskites used as light harvesters. The devices achieved high power conversion efficiencies.

A process of forming a thin film photoactive layer of an optoelectronic device comprising: providing a substrate having a surface comprising or coated with a metal M selected from at least one of Pb, Sn, Ge, Si, Ti, Bi, or In; and converting the metal surface or metal coating of the substrate to a perovskite layer.

Organic compounds suitable for organic layers of electronic devices that show reduced driving voltage, increased luminous efficiency and/or increased power efficiency.

Hybrid organic-inorganic perovskite thin films with average grain sizes of at least 50 micrometers were prepared and employed in solar cells. The PCE values of the solar cells did not degrade with the direction or the scan-rate of the applied voltage. The larger average grain sizes are believed to assist in reducing the influence of defect states on carrier recombination. The tunability of PCE with substrate temperature may be correlated to the quality of the crystalline perovskite formed using the hot-casting procedure. The larger average grain sizes lead to good crystalline quality, low defect density, and high carrier mobility. The process for growing hybrid organic-inorganic perovskites may be applicable to the preparation of other materials to overcome problems related to polydispersity, defect formation, and grain boundary recombination.

In the organic electroluminescent device having at least an anode, a hole injection layer, a first hole injection layer, a second hole injection layer, a light emitting layer, an electron transport layer and a cathode in this order, the hole injection layer includes an arylamine compound of the following general formula (1) and an electron acceptor.

##STR00001##

In the formula, Ar.sub.1 to Ar.sub.4 may be the same or different, and represent a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group.

Provided is a display device 100 that includes a display panel having flexibility (an organic EL panel 1 as an example), and an optical member 2 having flexibility, arranged so as to be stacked on the display panel, wherein the display panel and the optical member 2 are stacked and bonded in a bent state, and thereafter stretched into a flat shape.

According to the present invention, there are provided pyrimidine derivatives represented by the following general formula (1). The pyrimidine derivatives of the invention are novel compounds and feature (1) good electron injection property, (2) high electron mobility, (3) excellent hole blocking property, (4) good stability in their form of thin films, and (5) excellent heat resistance.

##STR00001##

The present invention relates to a novel anthracene derivative, for an organic light-emitting device, and an organic light-emitting device comprising same, the anthracene derivative enabling excellent device characteristics when used as a light-emitting material.

Objects of the present invention are to provide an organic semiconductor element in which carrier mobility is high, variation of mobility is suppressed, and temporal stability under high temperature and high humidity is excellent, and a manufacturing method thereof, to provide a novel compound suitable for an organic semiconductor, and to provide an organic semiconductor film in which mobility is high, variation of mobility is suppressed, and temporal stability under high temperature and high humidity is excellent, a manufacturing method thereof, and an organic semiconductor composition that can suitably form the organic semiconductor film.

The organic semiconductor element according to the present invention is an organic semiconductor layer containing a compound having a constitutional repeating unit represented by Formula 1 and having a molecular weight of 2,000 or greater.

D-A  (1)

The present invention provides a circularly polarizing plate that makes it possible to realize a bendable display device having reduced reflectivity and reflective tint and has excellent bending resistance, and a display device including a circularly polarizing plate. The circularly polarizing plate of the present invention is a circularly polarizing plate used for a bendable display device and includes a polarizer, and a phase difference film that is arranged on one side of the polarizer. The phase difference film includes a λ/2 plate and a λ/4 plate, the λ/2 plate and the λ/4 plate each include a liquid crystal compound, and a slow axis direction of the phase difference film is adjusted to define an angle of 75 to 105 degrees with respect to a bending direction of the display device.