Laser Scribing for Electrode Patterning of Perovskite Spectrometer-Grade CsPbBr₃ Gamma-ray Detectors

Abstract

Making semiconductor radiation detectors that work at room temperature relies heavily on the deposition and pixelation of electrodes. Electrode patterning of perovskite solar cells widely implements laser scribing techniques, which is a convenient, scalable, and inexpensive technique. However, this method has not found its application in radiation detector patterning yet, and the question whether laser scribing can achieve high-quality patterns with minimum damage to a detector crystal and low interpixel cross-talk remains largely unanswered. To prove that laser scribing is a practical method for electrode patterning on perovskite CsPbBr3 detectors, we use the material to create a variety of patterns. A very low lateral leakage current (60 nA at 10 V) and high mobility-lifetime product (9.7(3) × 10–4 cm2/V) were observed between the pixel and the guard ring in tests of single-pixel devices with a separation of 200 or 100 μm between the central electrode and the guard ring. The 122 and 136 keV photopeaks in 57Co gamma-ray spectra were very well resolved with an energy resolution of up to 6.1% at 122 keV. A further reduction in gap size to 50 μm is conceivable, but more process optimization is needed.

Using N–I–N Photodiodes Made of Perovskite Single Crystals for Low Noise Gamma-Ray Spectroscopy

“…29−31 Except of improving the crystallization of LHPSCs with fewer defects, designing a bandenergy barrier is imperative to further suppress the contribution of intrinsic defects for low-noise gamma-ray photodiodes. 32,33 As shown in Figure 1b, the P-type layer in a PIN photodiode is replaced by an N-type layer to form an NIN photodiode. In the structure of the NIN photodiode, the defect-induced, photon-activated, and injected holes are suppressed by the symmetrical blocking layers.…”

“…Q activated in thick gamma-ray photodiodes is much smaller than Q activated for the PIN photodiodes for visible photons. Therefore, most solution-processed LHPSCs may show great performance in the detection of visible photons, but for gamma-ray detection, most solution-processed LHPSCs can only identify the number of photon peaks and cannot achieve gamma-ray spectroscopy with good energy resolution. − Except of improving the crystallization of LHPSCs with fewer defects, designing a band-energy barrier is imperative to further suppress the contribution of intrinsic defects for low-noise gamma-ray photodiodes. , …”

Bright Innovations: Review of Next-Generation Advances in Scintillator Engineering

“…Solution-processed hybrid perovskites were shown to have the potential as photodetectors . This facilitates the construction of a futuristic hybrid detector material, combining a scintillator with a photodetector with vast deposition and patterning versatility . Discussions with peers have shown us another direction in photodetection, which could yield creative ideasbioinspired dyes, such as melanin, chlorophyll, and carotenoids.…”

Stable photocurrent–voltage characteristics of perovskite single crystal detectors obtained by pulsed bias

“…Typically, the µτ can be obtained by strongly absorbing ionizing radiation, i.e., irradiating the sample with α-particles or γ-rays and investigating the charge collection efficiency. [8,9] Additionally, we can also determine µτ by visible light with energies surpassing the bandgap to stimulate carriers within the material, enabling the investigation of photocurrent-voltage properties. [10,11] To study the photocurrent-voltage characteristics of perovskites, it is necessary to gradually increase the bias voltage for a given light illumination with the aim of saturating the photocurrent.…”