Patent ID: 8853531

Claim:
Apparatus for radiant energy conversion, the apparatus comprising: a semiconductor photocathode having a positive electron affinity surface; and an anode separated from said photocathode; wherein absorption of incident radiation in said photocathode during operation of said apparatus gives rise to a distribution of electrons in a conduction band of said cathode; wherein some or all electrons in said distribution are thermalized with respect to a temperature of said photocathode, wherein said temperature of said photocathode is greater than 200° C. during operation of said apparatus; wherein some or all electrons in said distribution are emitted from said photocathode and received by said anode; wherein a potential difference is established between said photocathode and said anode by electrons received at said anode to provide output electrical power; wherein said photocathode comprises a surface coating to determine said positive electron affinity; wherein an electron affinity of said photocathode is between 0 eV and 1 eV, and wherein said photocathode can operate at an operating temperature greater than 200° C.