Numerical Study of the Effects of Hetero-Interfaces, Polarization Charges, and Step-Graded Interlayers on the Photovoltaic Properties of (0001) Face GaN/InGaN p-i-n Solar Cell

Polarization-Engineered InGaN/GaN Solar Cells: Realistic Expectations for Single Heterojunctions

“…The origin of such band-bending is the polarization-induced electric filed, which not only compensates the normal built-in field of the junction since they have opposite directions, but severely overcomes it with its great magnitude upon increasing InN MF or/and decreasing plastic relaxation percentage of the films [9], [20], [21]. Also, in such designs, as the indium content or/and strain degree rises, the escalating positive polarization charges at the pGaN/InGaN hetero-interface create an additional potential barrier.…”

“…Thus, the most challenging issue dealing with p-on-n structures is to mitigate the polarization-induced electric field. The polarization effect can be effectively suppressed by inserting step-graded [20] or compositional graded layers between heterointerfaces [21], but both approaches require highly doped (5×10 18 cm −3 ) p-type InGaN regions, which is practically very difficult to realize, especially in the case of compositional graded p-InGaN.…”

Numerical Investigation of High-Efficiency InGaN-Based Multijunction Solar Cell

“…In our prior studies, the use of compositional grading layers had already been demonstrated to be one of the solutions to the detrimental polarization and barrier effects [16], [18]. The multijunction structure in this paper is therefore constructed based majorly on the concept that most of the subcells possess an n-GaN/i-InGaN/p-GaN structure.…”

“…Theoretical predictions reveal that, if the indium composition of the InGaN absorption layer is high, the photovoltaic characteristics might be too poor to have practical applications due to the aforementioned issues even though perfect crystalline quality of InGaN solar cell can be achieved. Fortunately, some specific designs in the solar cell structure were proposed, which have been demonstrated theoretically to be effective solutions for the detrimental barrier and polarization effects [16], [18], [19].…”

Spectral competition of chirped dual-wavelength emission in monolithic InGaN multiple-quantum well light-emitting diodes

“…In addition to the important issues of color rendering index (CRI), carrier localization due to the indium-rich nanostructures, and difficulty in growth of high indium-content alloys, there are some other significant problems which need to be solved toward the commercial realization of dual-wavelength monolithic InGaN MQW LEDs. 19 In this work, spectral competition of chirped dualwavelength emission in monolithic InGaN MQW LEDs is investigated numerically with the APSYS simulation program. 20 The reference LED structure used in this work is based on a real device fabricated in laboratory.…”