The main electrical characteristics of thermophotovoltaic converters based on p-InAsSbP/n-InAs/n-InAsSbP double heterostructures with a fully or partially removed substrate in a flip-chip structure are investigated. The influence of the resistance of different parts of the structure on the spatial distribution of the current density in the active region is shown, and the conditions for obtaining the most efficient collection of photocurrent / minimum current crowding are determined.