Fantoni A, Vieira M, Vygranenko Y, Fernandes M, Louro P
Electronics Telecommunication and Computer Department ISEL, R. Conselheiro Emílio Navarro, 1949-014 Lisboa, Portugal.
J Nanosci Nanotechnol. 2009 Jul;9(7):4254-8. doi: 10.1166/jnn.2009.m42.
We present in this paper results about the analysis of photocurrent and spectral response in a-SiC:H/a-Si:H pinpin and pinip structures. Our experiments and analysis reveal the photocurrent profile to have a strong nonlinear dependence on the externally applied bias and on the light absorption profile, i.e., on the incident light wavelength and intensity. Our interpretation points out the cause of such effect to a self biasing of the junctions under certain unbalanced light generation of carriers and to an asymmetric reaction of the internal electric fields to the externally imposed bias. The possibility to relate such a behavior to the light intensity and wavelength indicates realistic hypothesis of using these structures and this effect for color recognition sensors. We present results about the experimental characterization of the structures and numerical simulations obtained with the program ASCA. Considerations about electrical field profiles and inversion layers will be taken into account to explain the optical and voltage bias dependence of the spectral response. Our results show that in both structures the application of an external electrical bias (forward or reverse) mainly influences the field distribution within the less photo excited sub-cell.
我们在本文中展示了关于非晶硅碳氢化物/非晶硅pinpin和pinip结构中光电流和光谱响应分析的结果。我们的实验和分析表明，光电流分布对外加偏压和光吸收分布具有强烈的非线性依赖性，即对入射光的波长和强度有强烈的非线性依赖性。我们的解释指出，这种效应的原因在于在某些载流子产生不平衡的光照条件下结的自偏置，以及内部电场对外加偏压的不对称反应。将这种行为与光强度和波长联系起来的可能性表明，利用这些结构和这种效应制造颜色识别传感器是切实可行的假设。我们展示了这些结构的实验表征结果以及使用ASCA程序获得的数值模拟结果。为了解释光谱响应的光学和电压偏置依赖性，将考虑电场分布和反型层。我们的结果表明，在这两种结构中，施加外部电偏压（正向或反向）主要影响光激发较少的子电池内的场分布。
