“…This distance, determines the energy of utilized carriers. Even though the obtained values of the width of the minigap are not optimal to obtain maximal efficiency (Bremner et al, 2009;Luque & Martí, 1997;Shao et al, 2007), the increase in efficiency is significant as compared to the bulk solar cells (Kłos & Krawczyk, 2009). The impact of the discretisation of the valence band on the efficiency of the photovoltaic effect is be much lesser than that of the discretisation of the conduction band, and, in the first approximation, can be regarded as limited to a shift in valence band top in the evaluation of solar cell efficiency (Kłos & Krawczyk, 2009 …”