This video is part of the FREE online course PV1x Photovoltaic Energy Conversion, developed by Delft University of Technology. PV1x is part of the Solar Energy Engineering MicroMasters this section we discuss some solar cell design considerations. In this video we introduce the multijunction concept, that aims to reduce the spectral mismatch losses. Multijunction solar cells are discussed more extensively in the PV2x Photovoltaic Technologies course.