Abstract: A method of forming a nanometer-scale prominence and depression structure on a zinc oxide thin film in a wet-etching method, and the method includes the steps of: preparing a substrate; forming a nano structure having a height and a width of a nanometer range; forming the zinc oxide thin film on the substrate on which the nano structure is formed; and wet-etching the zinc oxide thin film, in which in the wet-etching step, zinc oxide having relatively low physical compactness is preferentially etched since the zinc oxide is positioned on the nano structure, and thus the prominence and depression structure is formed around the nano structure by the etching. The method is effective in that a thin film can be uniformly formed on the prominence and depression structure, and an electrolyte or an organic material may uniformly penetrate between the prominence and depression structure.

Abstract: An apparatus and method for measurement of radiation intensity for testing reliability of a solar cell, and a method for testing the reliability of the solar cell. The apparatus includes a first solar cell receiving a predetermined intensity of radiation or more to generate electricity, a second solar cell receiving a predetermined intensity of radiation or more to generate electricity; a temperature sensor sensing a temperature of the second solar cell; a cooler cooling the first solar cell; and a controller measuring the intensity of radiation applied to the first solar cell, and controlling the cooler to prevent the temperature of the first solar cell from increasing above a predetermined temperature depending on the temperature of the second solar cell sensed by the temperature sensor.

Abstract: Disclosed is a portable communication apparatus with a data-inputting expansion comprising a main housing having a display device; a rotatable housing having first and second data-inputting devices on its upper and lower surfaces, respectively, the rotatable housing rotatably connected to the main housing while facing the main housing; a connecting portion with a contact surface exposed on one side of the front surface of the main housing; a first terminal with a contact surface exposed on one side of the rear surface of the rotatable housing, the first terminal being connected to the first data-inputting device; and a second terminal with a contact surface exposed on the other side of the rear surface of the rotatable housing, the second terminal being connected to the second data-inputting device, wherein connection is made between the connecting portion and one of the first or second terminals, as chosen by the rotation of the rotatable housing.

Abstract: Disclosed is a portable communication apparatus with a data-inputting expansion comprising a main housing having a display device; a rotatable housing having first and second data-inputting devices on its upper and lower surfaces, respectively, the rotatable housing rotatably connected to the main housing while facing the main housing; a connecting portion with a contact surface exposed on one side of the front surface of the main housing; a first terminal with a contact surface exposed on one side of the rear surface of the rotatable housing, the first terminal being connected to the first data-inputting device; and a second terminal with a contact surface exposed on the other side of the rear surface of the rotatable housing, the second terminal being connected to the second data-inputting device, wherein connection is made between the connecting portion and one of the first or second terminals, as chosen by the rotation of the rotatable housing.