An optoelectronic bistable apparatus having a double heterojunction structure comprising a light-emitting first semiconductor layer of n type GaAs interlaid between a second semiconductor layer of n.sup.- type AlGaAs and a third semiconductor layer of p.sup.+ type AlGaAs, the second and third semiconductor layers having a broader energy gap than that of the first semiconductor layer. An extremely thin fourth semiconductor layer of p.sup.+ type GaAs with a high impurity concentration is deposited on the second semiconductor layer. A fifth semiconductor layer of n.sup.- type AlGaAs, n.sup.+ type AlGaAs and n.sup.+ type GaAs is formed on the fourth semiconductor layer. At least a portion of the fifth semiconductor layer which contacts the fourth semiconductor layer has a broader energy gap than that of the second semiconductor layer.