Electrical and Spectroscopic Properties of SiC Detectors
Authors:
Mykola Brynza,
Eduard Belas,
Petr Praus,
Jindrich Pipek,
Roman Grill
Abstract:
In this paper we compare suitability of three different semi-insulating bulk silicon carbide (SiC) materials for fabrication of radiation detectors. We prepared planar sensors with various metal contact combination and characterized detector quality by the alpha spectroscopy and I-V characteristic measurements. We observed that 4H-SiC material from the II-VI company is not suitable for radiation d…
▽ More
In this paper we compare suitability of three different semi-insulating bulk silicon carbide (SiC) materials for fabrication of radiation detectors. We prepared planar sensors with various metal contact combination and characterized detector quality by the alpha spectroscopy and I-V characteristic measurements. We observed that 4H-SiC material from the II-VI company is not suitable for radiation detector fabrication due to high concentration of vanadium doping. We also present a poor charge collection efficiency of the 4H-SiC Norstel material due to high concentration of residual impurities and we evaluated low mobility-lifetime product (alpha)= 3.5E-7 cm2/V from the alpha spectroscopy. We demonstrate that the 4H-SiC material from the Cree company is the best candidate for the production of radiation detectors. We evaluated mobility-lifetime product (alpha)= 5.4E-6 cm2/V using AuTi/SiC/TiAu contact structure.
△ Less
Submitted 10 January, 2020;
originally announced January 2020.
Deciphering the Effect of Traps on Electronic Charge Transport Properties of Methylammonium Lead Tribromide
Authors:
Artem Musiienko,
Jindrich Pipek,
Petr Praus,
Mykola Brynza,
Eduard Belas,
Bogdan Dryzhakov,
Mao-Hua Du,
Mahshid Ahmadi,
Roman Grill
Abstract:
Organometallic halide perovskites (OMHPs) have undergone remarkable developments as highly efficient optoelectronic materials for a variety of applications. Several studies indicated the critical role of defects on the performance of OMHP devices. Yet, the parameters of defects and their interplay with free charge carriers remain unclear. In this study we explore the dynamics of free holes in meth…
▽ More
Organometallic halide perovskites (OMHPs) have undergone remarkable developments as highly efficient optoelectronic materials for a variety of applications. Several studies indicated the critical role of defects on the performance of OMHP devices. Yet, the parameters of defects and their interplay with free charge carriers remain unclear. In this study we explore the dynamics of free holes in methylammonium lead tribromide (MAPbBr3) single crystals using the time of flight (ToF) current spectroscopy. By combining the current waveform (CWF) ToF spectroscopy and the Monte Carlo (MC) simulation, three energy states were detected in the band gap of MAPbBr3. Additionally, we found the trapping and detrapping rates of free holes ranging from a few us to hundreds of us and, contrary to previous studies, a strong detrapping activity was revealed. It was shown that these traps have a significant impact on the transport properties of MAPbBr3 single crystal devices, including drift mobility and mobility-lifetime product. To demonstrate the impact of traps on the delay of free carriers, we developed a new model of the effective mobility valid for the case of multiple traps in a semiconductor. Our results provide a new insight on charge transport properties of OMHP semiconductors, which is required for further development of this class of optoelectronic devices.
△ Less
Submitted 10 December, 2019; v1 submitted 23 September, 2019;
originally announced September 2019.