The development of human civilization was fueled by different energy sources throughout its history, with the past decades clearly showing a trend of using environment-friendly energy. Among the energy sources available from the Nature, solar energy has a special place [1, 2]. It is available in vast quantities, especially in countries with high insolation level such as México. Transformation of solar light into electricity takes place in photovoltaic devices – solar cells – that do not require much maintenance throughout their operation cycle and can function as stand-alone devices allowing the use of electrical equipment even in most remote areas. The energy produced by the solar cells during the day can be stored in accumulators and used during the night, making solar-powered equipment practically selfsustainable if the required number of sunlight hours per day is available. Currently, most commercial solar cells are made of silicon due to its vast availability and silicon technology that reached the state of perfection, allowing to achieve the conversion efficiency of almost 28% (single silicon cell, [3]). Actually, world production of photovoltaics is dominated by polycrystalline silicon cells representing 94% of the market [4]. These devices based on silicon wafers are called the "first generation" of photovoltaic technology. Monocrystalline silicon devices are effective but expensive. Similarly, solar cells based on other semiconductor materials, called "second generation", such as group II-VI and III-V heterostructures, are capable of efficiencies over 40% (GaInP/GaAs/GaInNAs, [3]) but depend significantly on the quality of the junction that may contain defects acting as effective recombination centers, reducing considerably the concentration of photo-generated carriers.