Molecular beam epitaxy grown 0.6 eV n∕p∕n InPAs∕InGaAs∕InAlAs double heterostructure thermophotovoltaic devices using carbon as the p-type dopant

Abstract

Beryllium (Be) has been previously shown to be an adequate p-type dopant for molecular beam epitaxy (MBE) grown 0.6eV n∕p∕n InGaAs∕InPAs double heterostructure thermophotovoltaic (TPV) devices. However, due to environmental, safety, and health operational concerns caused by airborne exposure to Be during cleaning operations in a MBE system, carbon (C) was investigated as a p-type dopant substitute. However, due to the amphoteric nature of C, it incorporates on the group-III site in InGaAsP material with high P content, making it n type. Therefore, to grow the n∕p∕n InGaAs double heterostructure TPV device, InAlAs was developed as the back surface field (BSF). By using C as the p-type dopant and InAlAs as the BSF, MBE grown 0.6eV n∕p∕n InPAs∕InGaAs∕InAlAs double heterostructure TPV devices were successfully made. The demonstrated room temperature reverse saturation current density (j0) value from this MBE grown device was ∼9μA∕cm2. This j0 value was only three times larger than the previous best MBE grown ...