Photovoltage formation across GaAs p–n junction under illumination of intense laser radiation

Peculiarities of photovoltaic effect in GaAs p–n junction under laser excitation at 10.6 and 1.06 μm wavelengths has been investigated experimentally. When photon energy is far less than the forbidden energy gap, the photovoltage is found to be caused by hot carrier electromotive force. When the junction is illuminated with intense Nd:YAG laser radiation, the photovoltage is recognized to consist of two components, U = U f + U ph . The first one U f is the fast component having polarity of thermoelectromotive force of hot carriers. The second one U ph is the slow component of opposite polarity, and it is caused by electron–hole pair generation due to two-photon absorption of laser radiation.