Solution processable, precursor based zinc oxide buffer layers for 4.5% efficient organic tandem solar cells

High‐Performance Polymer Tandem Solar Cells Employing a New n‐Type Conjugated Polymer as an Interconnecting Layer

“…For conventional tandem OSCs, the ICL structure is composed of a n-type metal oxide combined with p-type poly mer, such as ZnO/PEDOT:PSS [ 26 ] and TiO x /PEDOT:PSS, [ 11,27,28 ] or n-type metal oxide combined with p-type metal oxides, such as ZnO/MoO 3 . [ 29,30 ] Although these combinations often result in excellent device performance, the inorganic metal oxides may suffer from their intrinsic brittleness and may not be fully compatible with fl exible or wearable application of OSCs. In addition, in some cases the n-type metal oxides degrade by reacting with the acidic PEDOT:PSS and reduce the device stability.…”

An All‐Solution Processed Recombination Layer with Mild Post‐Treatment Enabling Efficient Homo‐Tandem Non‐fullerene Organic Solar Cells

“…For example, a recently reported SMA OSC achieved a high open circuit voltage ( V oc ) of 1.11 V, but its performance was limited by the insufficient absorption, as the active layer (≈120 nm) exhibited a maximum absorbance of only ≈0.4. One promising approach to increase the light harvesting, and thus the PCE of such SMA OSCs is to stack in series two sub‐cells containing the same active layer materials, forming the so‐called homo‐tandem device …”

Understanding the angle-independent photon harvesting in organic homo-tandem solar cells

“…So far, the maximum PCE in tandem solar cells has been achieved when the photo currents of both subcells have been matched, although, in non-matched devices, the stronger subcell may assist the weaker subcell with the extraction of charges [13]. The matching of photo currents very much depends on the optical field in the tandem device and hence the charge carrier generation profile [14,15]. Organic tandem devices comprise several thin layers with thicknesses on the order of the wavelength of the incident sunlight.…”