A diode-laser bar stack includes a plurality of diode-laser bars having different temperature dependent peak-emission wavelengths. An object of an embodiment of the disclosed invention is to provide a semiconductor device including a photoelectric conversion device with excellent characteristic through a simple process. The yarns provide greater surface area which helps to hold the gel compound in place when the gel compound is heated. As a result, the sidewalls of the gate trench do not form an undesired conductive path between the source and the drain of the transistor, thereby advantageously reducing the amount of parasitic current that flows between the source and drain during operation.