PROJECT TITLE :

Optimization of ZnO Front Electrodes for High-Efficiency Micromorph Thin-Film Si Solar Cells

ABSTRACT:

The quest for increased performances in skinny-film silicon micromorph tandem devices nowadays needs a rise of current density. This can be achieved with thin cells by combining both robust cell design and efficient light management schemes. In this paper, we determine three key needs for the transparent conductive oxide electrodes. Initial, sturdy lightweight scattering into massive angles is required on the whole helpful wavelength range: A front electrode texture with massive enough options is shown to grant a high total current (usually >twenty six mA/cm2 with a a pair of.4-μm-thick absorber material), whereas sharp features are reported to allow for top high cell current (>13 mA/cm2) and reduced reflection at the ZnO/Si interface. Second, sufficiently smooth substrate options are required to guarantee a high quality of the silicon active material, ensuring good and stable electrical properties (typically Voc around one.4 V). Third, conduction and transparency of electrodes must be cleverly balanced, requiring high transparent conductive oxide mobility (∼50 cm $^two$/V/s) to maintain the sheet resistance below thirty Ω/sq whereas keeping absorption as low as attainable. Optimization of these 3 key requirements using ZnO electrodes allowed us to realize high-potency micromorph devices with 13.5% initial and eleven.five% stabilized efficiency.