System Introduction
The Light Beam Induced Current Mapping System (LBIC) is a point by point scanning imaging detection technology; Characterize the micro area characteristics of optoelectronic devices (including solar cells) point by point through laser monochromaticity and convergence; And through two-dimensional scanning (Mapping), a planar distribution image of device parameters is formed to reflect its planar uniformity.
The system can be widely applied to the research of solar cells using various materials such as monocrystalline silicon, polycrystalline silicon, amorphous silicon (a-Si), cadmium telluride (CdTe), copper indium gallium selenide (CIGS), organic semiconductors, dye sensitization, micro nano particles, perovskite, etc., especially in the study of small area cells; It can also be applied to the research and development of GaAs, InP, GaN based discrete devices and detector array chips. Suitable for use by a wide range of scientific research personnel and enterprise R&D personnel.

Figure 1 Beam Induced Current Imaging Detection System (LBIC)
system composition
The system mainly consists of three parts: host, control system, and software platform. The host part includes a laser, a 3D microscope stage, a CCD detector, a standard detector, and a data collector; The control system consists of a laser control power supply, a power meter, a 3D microscope stage controller, a digital source meter, and a vacuum pump control power supply; The software includes scanning control, data acquisition control, data processing, and data storage.

system parameter

Measurement area (mm)2）	1´ 1~156 ´ 156
Laser (nm)	532980 (standard, other wavelengths optional)
Laser spot (μ m)	100, 50
Test current range (mA)	0.001~1
Test mode	LBIC mapping，LBIV mapping
Scanning step size (mm)	0.05, 0.1, 0.2, 0.5, 1, 2, 4, customizable
Scanning speed (points/s)	15
Measurement method	Single point, continuous scanning (mapping)

Function and Features
Short circuit current is imaged point by point, observing the uniform characteristics of battery current and array;
Single wavelength reflectance imaging point by point, observing the uniform characteristics of passivation film and surface velvet;
Single wavelength quantum efficiency;
Distribution of battery defects (grain boundaries and dislocations) (scale greater than 0.5 mm)
Overcoming the mismatch and inaccuracy between I-V testing and single point spectroscopy testing under large-area illumination
We can customize the wavelength and spot size according to specific user needs.

Application Cases
Polycrystalline silicon battery
125´125 mm²Beam induced current imaging (LBIC, left image) and voltage imaging (LBIV, right image) of polycrystalline silicon solar cell plane. As shown in Figure 2:

Figure 2 Current Imaging (LBIC, left image) Voltage Imaging (LBIV, right image)
Figure 2 reflects the distribution of defects and the uneven characteristics of short-circuit current. The left figure reflects the uneven distribution of short-circuit current in the battery plane, while the right figure reflects the lateral expansion characteristics of micro area voltage.
2 monocrystalline silicon batteries
1´1 cm²Three dimensional imaging of beam induced current and voltage in small area monocrystalline silicon solar cells. As shown in Figure 3:

Figure 3 Three dimensional imaging of current (LBIC, left image) and voltage (LBIV, right image)
It can visually observe the lateral voltage expansion characteristics of micro areas.
Short circuit current scanning imaging of 3-crystalline silicon
1´1 cm²Short circuit current scanning imaging of small area crystalline silicon solar cells, as shown in Figure 4:

Figure 4 Short circuit current scanning imaging of crystalline silicon
As shown in Figure 4, the yellow color in the bottom left corner indicates a decrease in short-circuit current, indicating leakage and reflecting process issues during battery preparation (such as mask cracking).
Two dimensional distribution of short-circuit current and parallel resistance in 4-crystalline silicon
Using a power meter reverse bias, measure the short-circuit current point by point to obtain a two-dimensional current distribution (left in Figure 5);
Obtain a two-dimensional scan image of parallel resistance under micro bias voltage using a power meter (as shown on the right in Figure 5).

Figure 5 1 ´ 1 cm²Two dimensional diagram of short-circuit current in crystalline silicon battery (left) 1 ´ 1 cm²Two dimensional diagram of parallel resistance of crystalline silicon battery (right)
As shown in the left figure of Figure 5, the black and white alternating arcs reflect the impurity patterns (black heart silicon) in the substrate. As shown in the figure on the right, through the numerical calibration on the right, it can be clearly seen that the parallel resistance values in the entire plane are between (1.5~3.5) ´ 10⁶ W changes internally, with the lower left corner higher than the upper right corner; The right center flower spot is the electrode pad.
5 Graphene batteries
The size and location of the active region of graphene batteries can be determined through LBIC images, and the distribution of their photoelectric response can be observed at a certain resolution. As shown in Figure 6, the square area with high brightness in the middle of the scanning image is the active area of the graphene battery.

Figure 6 Graphene Battery LBIC Image
From Figure 6, it can be seen that there are two dark spots in the active region, indicating the presence of defects in these two areas.
6 Organic batteries
The organic cell is composed of 6 organic solar cells combined, and short-circuit current scanning is performed on it, as shown in Figure 7 below:

Figure 7 Scanning image of organic battery short-circuit current
From Figure 7, it can be seen that the photoelectric performance of these 6 cells is inconsistent, and the photoelectric performance of each cell is also uneven. The following three cells are better than the above three cells, indicating that the uneven performance of the device is related to the preparation process.