This study investigates the efficient photocurrent generation in vertical heterostructures of layered materials, specifically graphene-MoS2-graphene and graphene-MoS2-metal junctions. The authors demonstrate that these structures can be designed to have broad junction areas for efficient photon harvesting. By integrating single or dual gates under and/or above the vertical heterostructure, the band slope and photocurrent generation can be tuned using an external electric field. The amplitude and polarity of the photocurrent can be modulated, achieving a maximum external quantum efficiency of 55% and internal quantum efficiency up to 85%. The study establishes a method to control photocarrier generation, separation, and transport processes using an external electric field, opening up new opportunities for photodetection and photovoltaic devices.This study investigates the efficient photocurrent generation in vertical heterostructures of layered materials, specifically graphene-MoS2-graphene and graphene-MoS2-metal junctions. The authors demonstrate that these structures can be designed to have broad junction areas for efficient photon harvesting. By integrating single or dual gates under and/or above the vertical heterostructure, the band slope and photocurrent generation can be tuned using an external electric field. The amplitude and polarity of the photocurrent can be modulated, achieving a maximum external quantum efficiency of 55% and internal quantum efficiency up to 85%. The study establishes a method to control photocarrier generation, separation, and transport processes using an external electric field, opening up new opportunities for photodetection and photovoltaic devices.