Utilization of photons with subband-gap energy, mostly near-infrared (NIR) photons, is highly desirable for photovoltaic cells; which can be achieved by adding an upconversion layer at the rear face of photovoltaic cells. Here, we study the upconversion luminescence properties of BaCl2:Er3+ phosphors and hexagonal NaYF4:Er3+ phosphors upon excitation of incoherent NIR sunlight with wavelength >800nm. Higher efficacious upconversion emissions of BaCl2:Er3+ phosphors have been observed in comparison with the well-known hexagonal NaYF4:Er3+ phosphors. We demonstrate that the photocurrent response from the thin-film-hydrogenated amorphous silicon solar cell attached with the BaCl2:Er3+ phosphor is notably enhanced under irradiation of incoherent NIR sunlight with wavelength >800nm. This judicious design may be envisioned to shorten the distance for the remarkable improvement of the power conversion efficiency of the next-generation photovoltaic cells and suggests a promising application for other NIR photoresponsive devices.