Topical review: pathways toward cost-effective single-junction III–V solar cells

Abstract

III–V semiconductors such as InP and GaAs are direct bandgap semiconductors with significantly higher absorption compared to silicon. The high absorption allows for the fabrication of thin/ultra-thin solar cells, which in turn permits for the realization of lightweight, flexible, and highly efficient solar cells that can be used in many applications where rigidity and weight are an issue, such as electric vehicles, the internet of things, space technologies, remote lighting, portable electronics, etc. However, their cost is significantly higher than silicon solar cells, making them restrictive for widespread applications. Nonetheless, they remain pivotal for the continuous development of photovoltaics. Therefore, there has been a continuous worldwide effort to reduce the cost of III–V solar cells substantially. This topical review summarises current research efforts in III–V growth and device fabrication to overcome the cost barriers of III–V solar cells. We start the review with a cost analysis of the current state-of-art III–V solar cells followed by a subsequent discussion on low-cost growth techniques, substrate reuse, and emerging device technologies. We conclude the review emphasizing that to substantially reduce the cost-related challenges of III–V photovoltaics, low-cost growth technologies need to be combined synergistically with new substrate reuse techniques and innovative device designs.

Direct GaAs Nanowire Growth and Monolithic Light‐Emitting Diode Fabrication on Flexible Plastic Substrates

“…In addition, low‐cost substrates have been considered critical for III–V device costs. [ 17 ] Furthermore, to the best of our knowledge, there are no reports of in situ growth of GaAs NWs, or even GaAs in general, directly on flexible plastic substrates.…”

CuI as a Hole-Selective Contact for GaAs Solar Cells

“…Some notable growth methods include hydride vapor-phase epitaxy, close-spaced vapor transport, and thin-film vapor−liquid−solid growth. 10 The first aspect studied in this work is the surface passivation of GaAs prior to the CuI deposition. GaAs has a high surface recombination velocity, and surface passivation is critical for efficient devices.…”

“…On the other hand, from the growth perspective, the i-GaAs film is easily achievable by various low-cost and high-yield growth methods, thereby rendering the results extendable more broadly to these systems. Some notable growth methods include hydride vapor-phase epitaxy, close-spaced vapor transport, and thin-film vapor–liquid–solid growth …”

“…9 As such, they can streamline the solar cell fabrication process, and in addition, they can be used on undoped absorber materials. This, in turn, can enable the use of various low-cost III−V fabrication techniques where doping is challenging 10 and avoid losses inherent in highly doped semiconductor layers. 9 Indeed, it has been estimated that carrier-selective contacts and low-cost crystal growth techniques are a promising pathway for price-competitive III− V solar cell fabrication.…”

FROM Si NANOWIRES TO Ge NANOCRYSTALS FOR VIS-NIR-SWIR SENSORS AND NON-VOLATILE MEMORIES: A REVIEW

“…Group IV semiconductors are intensively investigated [1][2][3][4] along with group III-V [5,6], II-VI [7][8][9][10][11][12][13][14][15][16][17] and IV-VI semiconductors [18,19].…”