| 초록 |
Tandem solar cells have great potential for increasing the efficiency with minimal cost. Lead halide based organic-inorganic hybrid perovskite materials have been considered as promising candidate for tandem cells. However, these materials generally are composed of organic cations such as methylammonium or formamidinium, they undergo compositional degradation due to humidity and heat. Cesium lead halides are prospective alternative due to its suitable band gap, high absorption and thermal stability. Cesium lead iodide is stable in an orthorhombic structure at room temperature, and when heated above 300oC, it changed to cubic structure. Unfortunately, the cubic phase is not stable in ambient atmosphere due to humidity and temperature. Therefore, the manufacture of high phase stability with suitable bandgap for tandem solar cells is still challenging, so we substituted iodine with a dash of bromide source to solve the structural instability with minimal band edge shift. |
