ScanPro Advance High-Resolution High-Speed Multi-Physical Quantity Scanning Comprehensive Test System

Comprehensive Photoelectric Test System

ScanPro Advance   A high-configured custom multi-functional photoelectric testing system with flexible configurations to meet complex customization requirements. A single instrument can integrate Raman spectroscopy, fluorescence spectroscopy, steady-state/transient photocurrent measurement, absorption spectroscopy, fluorescence lifetime measurement and electroluminescence measurement. It utilizes high-precision piezoelectric translation stages for spectral scanning, photocurrent scanning and fluorescence lifetime scanning. Its ultra-high stability microscope structure enables long-duration continuous testing. The multi-layer optical path supports testing with a variety of light sources including continuous-wave lasers, picosecond pulsed lasers, halogen lamps and xenon lamps.

Main technical parameters*

ScanPro AdvanceStructural Design

High-Stability Optical Path

The ScanPro Advance features a high-stability microscope stand design, suitable for stable long-duration testing.

ScanPro  AdvanceAdopting a highly stable microscope stand design, it is suitable for long-term stable testing. A 100× objective lens was used to observe the sample, and no visible changes were observed for more than 3 hours.

Multi-color Illumination Assisted Focusing

Five color filters can change the color of the illumination light. By illuminating with light of a color close to the laser wavelength and adjusting the focus, the laser spot can be precisely focused on the sample surface.

If a white illumination light source is used and the 405 nm laser is adjusted to the smallest spot size, the actual laser is not focused on the sample surface due to chromatic aberration in the imaging optical path, resulting in poor photocurrent scanning performance, as shown in Figure b. However, if a purple illumination light source is used to focus the 405 nm laser, the similar wavelengths of the illumination source and the laser can compensate for the chromatic aberration of the imaging system. This allows the laser to be accurately focused on the sample surface and yields high-resolution photocurrent scanning images, as shown in Figure d.

Cascaded Optical Path

ScanPro AdvanceUp to 3 layers of incident optical paths can be adopted, and each layer of incident optical path can be equipped with a maximum of 5 beam splitters or dichroic mirrors. Laser mounting brackets can also be used to install up to 3 free-space output lasers inside one light-shielding housing. Therefore, ScanPro Advance offers highly versatile optical expandability and can support complex optical tests.

Closed housing design to completely shield interference from ambient light.

Photocurrent test function

                                                                                                                                   Spot types (a) homogenized illumination spot, (b) laser illumination spot

In photocurrent testing, ScanPro Advance offers two different types of illumination spots. The homogenized illumination module converts the laser into a uniform small spot to irradiate the sample, and a white LED is provided as an indicator to show the laser irradiation position. The minimum spot size is 8 micrometers (with a 50× objective lens. The uniform spot also facilitates the calculation of optical power density during testing. The focused illumination spot directly focuses the laser on the sample surface to form a tiny Gaussian spot with a spot size of approximately 1 micrometer. It can be positioned at designated locations to excite the sample and is also used for photocurrent scanning.

Photocurrent scanning test (a) bright field, (b) scanning image of the corresponding area

Using a high-precision piezoelectric stage, ScanPro Advance enables scanning with a positioning accuracy of up to 20 nm over a maximum range of 100 microns. Given that the spot size is approximately 1 μm, the spatial resolution of photocurrent scanning is also 1 μm. During photocurrent scanning, the dark current varies over time due to changes in the device itself or air interference. If the photoresponse of the device is weak, the variation in dark current during scanning may be on the same order of magnitude as the photocurrent, resulting in blurry and unusable images. Metatest Suite controls the laser switch to measure photocurrent and dark current separately at each data point. Since the time interval between the two measurements at each data point is very short, the dark current changes minimally. This allows accurate measurement of the device's photocurrent value and acquisition of high-resolution photocurrent scanning images. An optional lock-in amplifier for photocurrent scanning can also eliminate the effects caused by dark current fluctuations.

The Metatest Suite software package provides unified control of all test equipment in the system and supports parameter scanning of up to 4 parameters (2 pairs), so photocurrent curves under different light intensities and voltages can be measured in a single run.

测试示例 （a）变光强测输出曲线，（b）固定光强测转移曲线 （c）光响应测试，（d）变光强测开关比

光谱测试功能

405nm荧光光谱测试光路和532nm拉曼光谱测量光路对两个波长的激光进行了专门的优化，使用100倍物镜时具有衍射极限的 光斑，因此在光谱扫描中可以提供极高的空间分辨率。 ScanPro Advance采用自由空间光路设计，样品的拉曼/荧光信号通过反射镜直接聚焦于光谱仪狭缝，具有很高的收集效率。 光谱仪使用了制冷型探测器具有极低的热噪声，可以进行长时间积分，两者相结合保证了微弱光谱测试的准确性。利用高精度压电 位移台，ScanPro Advance可以在最大100微米的范围内进行定位精度高达20nm的扫描，由于光斑尺寸在500nm左右（532nm激 光），光谱扫描空间分辨率也为500nm。Scanpro Advance光谱测试软件具有光谱Mapping数据快速处理，自动平滑，自动计算 积分，平均值，峰值位置，峰宽度等信息。

荧光光谱及扫描测试示例 （a）SiO2 /Si基底MoS2在100X物镜下明场图，蓝框为大区域，红框为小区域（b）PL光谱，（c）扫描区域30*30um， （d）扫描区域10*10um

拉曼光谱及扫描测试示例 （a）SiO2 /Si基底MoS2在100X物镜下明场图，蓝框为大区域，红框为小区域（b）Raman光谱，（c）扫描区域 30*30um，（d）扫描区域13*10um，插图为拉曼扫描截线图，显示扫描分辨率为400nm

偏振光谱测试

ScanPro Advance配备了电动起偏器和电动检偏器，可以自动调整入射激光的偏振方向。起偏器采用了固定的偏振片和可旋转 的半波片，在改变偏振方向的过程中激光能量没有变化。检偏器采用了宽带偏振片，可以覆盖250-4000nm的波长范围。Metatest Suite测试软件可以自动旋转起偏器或者检偏器，或者同步旋转起偏器和检偏器，旋转过程中可以自动记录光谱数据，从而快速测量 样品的偏振光谱数据。

偏振荧光及拉曼测试示例 ，使用532nm激光激发，对SiO2 /Si基底MoS2通过改变入射光偏振进行（a）偏振荧光光谱和（b）偏振拉曼光谱测试

荧光寿命光谱及Mapping 

Scanpro Advance可以选配荧光寿命测试功能，仪器通道宽度64ps，适用于钙钛矿，量子点等荧光寿命超过500ps的样品。探 测器安装于光谱仪上，可以通过转动光栅扫描光谱，得到样品不同波长的寿命曲线。对于短寿命的样品，可以选配时间通道宽度最 小813fs的tcspc测试系统，配合高速探测器和皮秒激光，仪器响应速度约22ps，可以测量大于10ps的荧光寿命。

荧光寿命测试（a）绿色晶体荧光寿命光谱，插图为PL光谱， （b） 不同波长下的荧光寿命图

配合高分辨的样品扫描测试系统，也可以进行荧光寿命Mapping。数据处理软件可以自动处理Mapping数据，利用最多3个指 数进行拟合，并且直接生成不同参数的Mapping图片。

荧光寿命扫描测试（a）明场图片，（b）荧光寿命扫描强度图，（c）荧光寿命扫描拟合平均寿命图，（d）荧光寿命扫描拟合τ1寿命图，（e）荧光 寿命扫描拟合τ2寿命图

吸收光谱测试

ScanPro Advance可以选配卤素灯光源进行吸收光谱测试，光谱范围390-1100nm。

50X物镜下的指示光纤图

利用指示光纤，可以直接观察光谱收集的位置，从而测量指定区域的光谱。ScanPro Advance使用100微米光纤收集样品反射 光，在100倍物镜下测量区域仅2微米，从而可以方便的测量微小样品指定区域的吸收光谱。 

利用背照式制冷型微型光谱仪高灵敏度低噪声的优势，单条光谱测试时间仅5ms，可以进行多次光谱平均准确测量样品的吸收 光谱。

（a）蓝宝石基底MoS2 （b） 蓝宝石基底WS2

电致发光光谱测试功能 

电致发光光谱模块可以测量样品的电致发光光谱，制冷型的背照CCD型光谱仪有着灵敏的光响应，可以测量样品的微弱发光， 测量范围300-1100nm。在Metatest Suite软件包中，可以自动扫描样品的激发电压并且测量发光光谱。使用光电探测器可以在微 秒尺度上测量样品发光的响应速度，根据样品的灵敏程度可以选择硅探测器或者PMT探测器测量样品发射的光强。

电致发光测试 （a） 为器件测试环境照片，（b）利用指示光纤显示了光谱测试位置， （c） 样品不同偏压下电致发光光谱，（d）电致发光的瞬态特性

波长连续可变光源 

荧光发射光谱（PLE）测试功能

mXenon氙灯模块采用了无色差光学系统，从而保证了紫外到红外一致的光谱分辨率以及更高的紫外光强，240-700nm波段 光功率密度均大于20mW/cm2（光斑尺寸13.3μm）。光学优化的快门和斩波器可以提供高速的开关速度（快门打开/关闭时间 900μs，斩波器打开/关闭时间1kHz下20μs）。

(a)300nm和500nm闪耀光栅不同波长下的光功率密度，(b)300nm和500nm闪耀光栅的不同波长下的光谱，(c)斩波器开关速度，(d)快门开关速度

电动衰减片轮除了可以通过软件调整输出光强，更具有恒功率输出模式，自动根据输出光波长调整光强，生成功率固定的照明光源。利用恒功率的光源，可以测量样品在指定光强下的响应率以及样品在不同波长激发下的I-V曲线。

a)恒功率输出模式，在波长250-1100nm下，固定照明光功率密度15mW/cm2，输出功率稳定性3%，输出曲线和在波长350-650nm下，固定照明光功率密度50mW/cm2，功率稳定性1%。照明范围直径13微米，(b)在固定照明光功率密度15mW/cm2下测得硅探测器响应率曲线图(红线)，蓝线为参考值，(c)不同波长下的I-V曲线

通过改变激发光波长激发样品荧光，并且固定激发光功率，配合光谱仪可以测量样品的荧光发射光谱(PLE)。通过MetatestSuite可以自动改变入射光波长并且记录荧光光谱，快速获得PLE数据。

(a)SiO2/Si基底MoS2的PLE光谱图，(b)不同激发波长下，对发射光谱在波长范围为650-700nm积分图，

(c)不同激发波长对发射光谱的二维强度图