Abstract: Disclosed is an organometallic complex capable of variable phosphorescence characteristics and yellow emission at high luminance. The organometallic complex has a structure represented by a formula (G1), where at least one of R4, R5, R6, and R7 is a phenoxy group, M is a Group 9 metal or a Group 10 metal, and n is 2 when the central metal M is a Group 9 element, or n is 1 when the central metal M is a Group 10 element.

Abstract: An object is to provide a photosensor utilizing an oxide semiconductor in which a refreshing operation is unnecessary, a semiconductor device provided with the photosensor, and a light measurement method utilizing the photosensor. It is found that a constant gate current can be obtained by applying a gate voltage in a pulsed manner to a transistor including a channel formed using an oxide semiconductor, and this is applied to a photosensor. Since a refreshing operation of the photosensor is unnecessary, it is possible to measure the illuminance of light with small power consumption through a high-speed and easy measurement procedure. A transistor utilizing an oxide semiconductor having a relatively high mobility, a small S value, and a small off-state current can form a photosensor; therefore, a multifunction semiconductor device can be obtained through a small number of steps.

Abstract: Display bright in contrast can be obtained without discrination and flicker in the display device of the direct vision type whose pixel pitches are short to 20 ?m or less. A liquid crystal panel is driven through the frame inverse driving method, and the vertical frame frequency is set to 120 Hz or more. Also, each of the pixels is arranged to correspond to one of R, G and B of color filters disposed on a TFT substrate side.

Abstract: A method of repairing a light emitting device which makes high quality image display possible even if a pin hole is formed during formation of an EL layer is provided. The method of repairing a light emitting device is characterized in that a reverse bias voltage is applied to an EL element at given time intervals to thereby reduce a current flowing into an EL element when the reverse bias voltage is applied to the EL element.

Abstract: An object is to provide a photoelectric conversion element having a side surface with different taper angles by conducting etching of a photoelectric conversion layer step-by-step. A pin photodiode has a high response speed compared with a pn photodiode but has a disadvantage of large dark current. One cause of the dark current is considered to be conduction through an etching residue which is generated in etching and deposited on a side surface of the photoelectric conversion layer. Leakage current of the photoelectric conversion element is reduced by forming a structure in which a side surface has two different tapered shapes, which conventionally has a uniform surface, so that the photoelectric conversion layer has a side surface of a p-layer and a side surface of an n-layer, which are not in the same plane.