Free-space terahertz radiation from a LT-GaAs-on-quartz large-area photoconductive emitter.
Free-space terahertz radiation from a LT-GaAs-on-quartz large-area photoconductive emitter.
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DOI：
10.1364/oe.24.026986
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发表时间：
2016-11
期刊：
影响因子：
3.8
通讯作者：
D. R. Bacon;A. Burnett;M. Swithenbank;C. Russell;Lianhe H. Li;C. Wood;J. Cunningham;E. Linfield;A. Davies;P. Dean;J. Freeman
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文献类型：
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作者：
D. R. Bacon;A. Burnett;M. Swithenbank;C. Russell;Lianhe H. Li;C. Wood;J. Cunningham;E. Linfield;A. Davies;P. Dean;J. Freeman
我们报道了大面积光电导太赫兹（THz）发射器，其具有使用剥离转移工艺在石英衬底上制造的低温生长GaAs（LT-GaAs）有源层。这些设备相比，相同的LT-GaAs发射器时，制造的生长基板上。我们发现，转移的设备显示出更高的光到太赫兹转换效率和显着更大的击穿场，我们归因于在衬底中的寄生电流减少。通过这些改进，我们证明了在最大工作电压下发射的太赫兹场强度增加了~8倍。此外，我们发现这些设备用于光电导检测时，我们解释通过减少寄生衬底电流和减少空间电荷积累在设备中的组合，提高了性能。
We report on large-area photoconductive terahertz (THz) emitters with a low-temperature-grown GaAs (LT-GaAs) active layer fabricated on quartz substrates using a lift-off transfer process. These devices are compared to the same LT-GaAs emitters when fabricated on the growth substrate. We find that the transferred devices show higher optical-to-THz conversion efficiencies and significantly larger breakdown fields, which we attribute to reduced parasitic current in the substrate. Through these improvements, we demonstrate a factor of ~8 increase in emitted THz field strength at the maximum operating voltage. In addition we find improved performance when these devices are used for photoconductive detection, which we explain through a combination of reduced parasitic substrate currents and reduced space-charge build-up in the device.