filling factor (FF)

The term fill factor is used in memory technology, photovoltaics, projectors and microdisplays, LCD displays and OLED displays.

1. In memory technology, the fill factor stands for empty memory locations in an ordered data structure. These free memory locations are kept free for data sets that are stored there according to the specified index scheme so that the indexing structure is not interrupted. The fill factor is the percentage of free memory locations.
2. In photovoltaics, the fill factor( FF) is an important parameter for their quality. It indicates how well a solar cell collects charge carriers emitted by light radiation. The fill factor depends on the type of solar cell and whether it is a silicon-based solar cell or another semiconductor material.
   

   I-V characteristic of a solar cell

   For solar cells, there are two power values: the Maximum Power Point( MPP) (light area) and the maximum possible power, which is calculated from the short-circuit current and the open-circuit voltage ( blue area). The fill factor is defined as the ratio of the MPP value to the theoretical power value and is always less than 1. Monocrystalline and polycrystalline solar cells achieve fill factors between 0.7 and 0.8, while for amorphous the FF values are between 0.5 and 0.7.
3. In projectors and LCD displays, the area ratio of the LCD pixels to the total area is increased to increase the luminous efficacy by reducing the web width between the individual pixels. The ratio of pixel area to total area is called the fill factor. LCD displays, OLED displays and micro- LED displays achieve fill factors of over 90%. The higher the fill factor, the higher the light yield.