What causes shunt resistance in solar cells?

Shunt resistance is due to non-idealities, mainly impurities near the p-n junction, which cause partial shorting of the junction. That is, if an impurity can join the front and back sides of the solar cell then it is responsible for shunt resistance.

What is shunt resistance of solar cell?

Low shunt resistance causes power losses in solar cells by providing an alternate current path for the light-generated current. Such a diversion reduces the amount of current flowing through the solar cell junction and reduces the voltage from the solar cell.

What is recombination losses in solar cells?

Recombination losses effect both the current collection (and therefore the short-circuit current) as well as the forward bias injection current (and therefore the open-circuit voltage). Recombination is frequently classified according to the region of the cell in which it occurs.

What is recombination in solar cells?

In a solar cell, recombination acts to restore the non-equilibrium light generated electron hole pair (EHP) population to its thermal equilibrium value. The three types of recombination in a bulk semiconductor are: radiative, non-radiative and auger recombination.

What is shunt resistance and series resistance?

The shunt resistance has no effect on the short circuit current while it reduces the open circuit voltage. The series resistance, however, does not change the open circuit voltage but reduces the short circuit current.

How do series resistance and shunt resistance of a solar cell affect the fill factor?

Series and shunt resistances are parasitic elements to represent losses in the device (solar cell). Both series and shunt losses degrades the fill factor and efficiency of a solar cell.

How can recombination loss be reduced?

These recombination losses can be mitigated through two basic types of passivation, chemical and electrical. Chemical passivation aims at reducing the surface trap states by bonding to the surface atoms either hydrogen atoms, another semiconductor film, or some other dielectric materials.

What is the effect of recombination time on quantum efficiency?

Charge recombination causes a drop in the external quantum efficiency. The ideal quantum efficiency graph has a square shape, where the QE value is fairly constant across the entire spectrum of wavelengths measured.

What is recombination current?

electric-current semiconductor-physics. This term is used frequently to describe the mechanism of current flow in a forward biased PN junction. It is called “recombination current”, where recombination is the process of conduction electrons filling holes in the valence band, thus eliminating an electron-hole pair.

What is the process of recombination?

Recombination is a process by which pieces of DNA are broken and recombined to produce new combinations of alleles. This recombination process creates genetic diversity at the level of genes that reflects differences in the DNA sequences of different organisms.

What is shunt resistance diode?

The shunt resistance is defined to be the inverse slope of the I-V curve at the 0 V point. Calculating the slope of the curve at the 0 V point is time-intensive, so the generally accepted practice in the industry is to measure the current I at V = 10 mV, and apply Ohm’s law to find the shunt resistance Rsh.

What is the effect of series resistance of solar cell?

The main impact of series resistance is to reduce the fill factor, although excessively high values may also reduce the short-circuit current. Schematic of a solar cell with series resistance.

What is shunt resistance in solar panels?

Shunt Resistance. Significant power losses caused by the presence of a shunt resistance, RSH, are typically due to manufacturing defects, rather than poor solar cell design. Low shunt resistance causes power losses in solar cells by providing an alternate current path for the light-generated current.

What are the common causes of shunt resistance?

For exemple, you can have aluminum spiking through the main junction, you can have bad edge isolation (if the cell is small) and so on Shunt resistance is due to non-idealities, mainly impurities near the p-n junction, which cause partial shorting of the junction.

How does a solar cell shunt circuit work?

Look at the standard simple one-diode equivalent circuit of a solar cell: Shunts are represented by an ohmic resistor located (modulo series resistance) between the two terminals of the solar cell. So, the current flowing through the shunt (i) shows a linear current–voltage characteristic and (ii) consists of majority carriers only.

How do you combine series and shunt resistances?

To combine the effect of both series and shunt resistances, the expression for FFsh, derived above, can be used, with FF 0 replaced by FF s 1. The overall equation then becomes; and by combining the above equations, the net equation for FF becomes;