In1-xGaxAs1-yPy/InP-based multiple quantum well (MQW) solar cell structures with built-in sequential resonant tunneling were experimentally investigated. The MQW region extended the lower edge of the solar cell absorption compared to the control non-MQW InP sample. An average increase of 11% in photovoltaic efficiency of the MQW sample over the control sample was observed. The measured open circuit voltage (Voc) was found to be in good agreement with the predicted value. The bias and excitation wavelength dependences of photoluminescence and photocurrent at room temperature were used to investigate carrier escape and recombination dynamics in the MQW and control samples. © 1998 American Institute of Physics.