The introduction of quantum objects (quantum wells, quantum dots, etc.) into the space charge region of the solar cel (SC) gives a positive result in increasing the device photogenerated current [1, 2]. However, the introduction of quantum objects leads to a negative effect - a drop in open circuit voltage. In the triple-junction GaInP/GaAs/Ge SCs, introducing a quantum object into a GaAs subcell gives an additional positive effect — improving of InGaP and GaAs subcels photogenerated currents balance. The purpose of the work is to determine the possibility of using hybrid quantum objects (quantum well-dots (QWD)) in a GaAs subcell. For the first time, the temperature dependences of the external quantum yield (EQE) and electroluminescence spectra (EL) of GaAs subcells with QWD were measured. The important characteristics of a quantum object - the sum of donor-like and acceptor-like levels depths, Ed + Ea, has been determined. It has been found that QWD included in GaAs subcell absorbs photons with wavelength more than 600 nm.