A layered structure includes a thyristor and a light-emitting element. The thyristor at least includes four layers. The four layers are an anode layer, a first gate layer, a second gate layer, and a cathode layer arranged in this order. The light-emitting element is disposed such that the light-emitting element and the thyristor are connected in series. The thyristor includes a semiconductor layer having a bandgap energy smaller than bandgap energies of the four layers.

A light-emitting component includes a light-emitting element, a driving thyristor, and a light-absorbing layer. The light-emitting element emits light of a predetermined wavelength. The driving thyristor causes the light-emitting element to emit light or causes an amount of light emitted by the light-emitting element to increase, upon entering an on-state. The light-absorbing layer is disposed between the light-emitting element and the driving thyristor such that the light-emitting element and the driving thyristor are stacked, and absorbs light emitted by the driving thyristor.

A light-emitting component includes a substrate, a light-emitting element, a thyristor, and a light-transmission reduction layer. The light-emitting element is disposed on the substrate. The thyristor causes the light-emitting element to emit light or causes an amount of light emitted by the light-emitting element to increase, upon entering an on-state. The light-transmission reduction layer is disposed between the light-emitting element and the thyristor such that the light-emitting element and the thyristor are stacked, and suppresses light emitted by the thyristor from passing therethrough.

A semiconductor device includes an n-type ohmic contact layer, cathode and anode electrodes, p-type and n-type modulation doped quantum well (QW) structures, and first and second ion implant regions. The anode electrode is formed on the first ion implant region that contacts the p-type modulation doped QW structure and the cathode electrode is formed by patterning the first and second ion implant regions and the n-type ohmic contact layer. The semiconductor device is configured to operate as at least one of a diode laser and a diode detector. As the diode laser, the semiconductor device emits photons. As the diode detector, the semiconductor device receives an input optical light and generates a photocurrent.