瞬态光栅光谱仪 HARPIA-TG

  • 几分钟内的载流子扩散系数!
  • 无创测量技术
  • 全自动计算机控制
  • 光栅周期的连续设置
  • 灵敏度低至 µJ/cm² 激励水平
  • 先进的测量和分析软件
  • 光致发光(PL)测量选项

特性

  • 几分钟内的载流子扩散系数!
  • 无创测量技术
  • 全自动计算机控制
  • 光栅周期的连续设置
  • 灵敏度低至 µJ/cm² 激励水平
  • 先进的测量和分析软件
  • 光致发光(PL)测量选项

HARPIA-TG 是一种瞬态光栅光谱仪,用于测量扩散系数和载流子寿命。测量基于激光诱导的瞬态光栅(LITG)技术,该方法通过全光学手段同时观察非平衡载流子复合和扩散。HARPIA-TG 可用于表征电气非导体或非荧光样品。它适用于半导体材料和衍生物,例如碳化硅(SiC),氮化镓(GaN),钙钛矿,有机和无机太阳能电池,量子点甚至复杂的纳米结构,如量子阱。

  • 瞬态光栅光谱学
  • 单波长的瞬态吸收

The principle of a LITG measurement is depicted in the figure on the right. A pair of ultrashort pulses are overlapped both spatially and temporally at the sample plane. Angular separation of the excitation beams causes them to interfere at their crossing. The period of the interference pattern Λ depends on the beam intersection angle and the pump wavelength.

Excitation by a periodic pattern creates a spatially-modulated excited carrier distribution and, effectively, a periodic modulation of the refractive index. Therefore, this pumping geometry produces a transient grating from which a temporally-delayed probe pulse can diffract. Over time, the laser-induced grating decays due to carrier recombination (electronic decay with the rate of τR) and carrier diffusion (spatial decay with the rate of τD ). The diffusion term depends on the transient grating period: fine gratings (small Λ values) diffuse faster than coarser ones (large Λ values).  Accordingly, if we measure the temporal behavior of the diffracted signal over a series of different periods Λ, we can determine the carrier diffusion coefficient D[cm2/s] from the relationship,

where τG is the net decay rate of the transient grating.

Parameter Value
扩散系数 0.1 – 50 cm2/s
载体寿命 1 ps – 80 ns

I.

Transient decay dynamics are measured at various grating periods Λ. HARPIA-TG allows continuous tuning of the excitation grating period. Periods ranging from 1.15 to 15 μm (depending on the pump wavelength) can be formed at the sample plane.

II.

Data obtained at each grating period is fit to an exponential decay. The retrieved reciprocal decay constants are plotted
as a function of the inverse square of the grating period. Tangent of this curve provides the carrier diffusion coefficient (at the given carrier concentration and temperature), while the zero-intercept point (Λ = ∞ μm) provides the intrinsic carrier recombination rate τR.

III.

Experiment is repeated at various excitation intensities to obtain a comprehensive dependence of the diffusion coefficient on the non-equilibrium carrier concentration.

Polarization and pump wavelength control enables more advanced spin grating and thermal grating measurements, respectively.

型号 HARPIA-TG
光栅记录 1) 340 – 560 nm
探测波长 2) 1030 nm
光栅周期 3) 1.15 – 15 μm
脉宽 < 290 fs
延迟范围 高达 8 ns
  1. 可扩展至长波(可见光/近红外)。详情请联系 sales@lightcon.com
  2. 可根据需求提供 SH(515 nm)或基于 OPA 的探测。详情请联系 sales@lightcon.com
  3. 取决于激发波长。
型号 HARPIA-TG
扩散系数 0.1 – 50 cm2/s
载体寿命 1 ps – 80 ns
型号 HARPIA-TG
尺寸 (长 × 宽 × 高)
730 × 420 × 188 mm

HARPIA-TG 瞬态光栅光谱仪

产品数据表

产品目录 27/06/2023, 1.5 MB.

HARPIA 综合光谱系统

产品数据表

产品目录 27/06/2023, 0.7 MB.

飞秒激光器飞秒科研系统

产品目录

产品目录 22/07/2023, 16.6 MB.

Femtosecond Laser Systems for Science

英文版产品目录

产品目录 04/09/2023, 16.6 MB.