ZAP! Introducing the Zero-bias Avalanche Photodiode

A novel heterostructure p-n junction diode is described which provides a photocurrent gain of 2 under zero external bias conditions. The necessary energy required to produce the additional electron-hole pair would be supplied by the internal electric field associated with the heterojunction energy gap difference. The ZAP diode structure has energy conversion applications as a photovoltaic detector whose efficiency may be enhanced by as much as 25% over that obtainable using homojunction solar cells. The device has, however, yet to be built.