Efficient vacuum deposited p-i-n and n-i-p perovskite solar cells employing doped charge transport layers

Methylammonium lead halide perovskites have emerged as high performance photovoltaic materials. Most of these solar cells are prepared via solution-processing and record efficiencies (>20%) have been obtained employing perovskites with mixed halides and organic cations on (mesoscopic) metal oxides. Here, we demonstrate fully vacuum deposited planar perovskite solar cells by depositing methylammonium lead iodide in between intrinsic and doped organic charge transport molecules. Two configurations, one inverted with respect to the other, p-i-n and n-i-p, are prepared and optimized leading to planar solar cells without hysteresis and very high efficiencies, 16.5% and 20%, respectively. It is the first time that a direct comparison between these two opposite device configurations has been reported. These fully vacuum deposited solar cells, employing doped organic charge transport layers, validate for the first time vacuum based processing as a real alternative for perovskite solar cell preparation

An overview about the use of electrical doping of charge carrier transport layers in OLEDs and further organic electronic applications

Electrical doping of organic layers is now a well established method for building highly efficient and long living OLEDs. A unique class of OLED devices called PIN-OLEDs based on redox doping technology is emerging as one key technology for OLED applications. These devices exhibit high power efficiency and long life time, which are critical parameters for commercial success. Moreover, PIN OLEDs offer high degree of freedom in choosing layer structures for optimizing the device performance for specific lighting and display applications. For example, optimizing color and power efficiency of OLEDs can be easily achieved without compromising the device operating voltage. It is worth to mention that PIN OLEDS, especially the red emitting PIN OLEDs, exhibit record breaking half life time of more than one million hours with the starting device brightness of 1000 cd/m(2). The doping technology also offers benefits to other organic electronic devices such as OTFTs and photovoltaic devices. This paper briefly discusses the improvements made on the OLED device performance such as power efficiency and lifetime using doped transport layers. Few examples of device optimization using doped layers are presented in detail. In addition, a brief discussion on performance of doped transport layers in photovoltaics is also presented