Damp heat stable doped zinc oxide films

Environmental stability of highly conductive nominally undoped ZnO layers

“…The observed deterioration of Hall mobility, specifically pronounced for the ZnO/b-ZnO coating, suggests electronic changes caused by water vapors that can get adsorbed at the exposed film surface and/or diffuse within the film through accessible columnar and grain boundaries [6], [7], [8]. It is known that the adsorbed water molecules and their products (e.g., formed hydroxides) act as electron traps.…”

The impact of atmospheric species on the degradation of CIGS solar cells

“…Since it is known that increased resistance of ZnO:Al is often a reason for CIGS solar cell degradation, in earlier work ZnO:Al layers [3] were already tested under several atmospheric gases, showing a large performance deterioration due to combined water and CO 2 exposure, while it was stable under many other conditions. Based on ZnO:Al degradation experiments, it can be expected that CO 2 is important [3][4][5], but this has not been studied yet. Therefore, the impact on complete CIGS solar cells is yet unknown, but it can be expected that the combined impact of water and CO 2 will be detrimental for the ZnO:Al layer of the solar cells, while other layers might be affected by different combinations.…”

Environmental stability of high-mobility indium-oxide based transparent electrodes

“…In fact, capping of DH-sensitive TCOs to improve their stability to heat and humidity is a known effective approach, as demonstrated earlier for ZnO electrodes. 16,34,35 In summary, we have studied the sensitivity to heat and humidity of sputtered ITO, IO:H, IZO, and IO:H/ITO bilayers front contacts used in solar cells by DH test. We found that polycrystalline ITO and amorphous IZO films feature high stability to heat and humidity, thus promising long term stability, needed for large-scale deployment of solar cells, whereas polycrystalline IO:H films degrade under DH exposure.…”