What you are suggesting is an organic photosynthesizer,but that's not necessary when you already have plants that have genetically adapted for millions of years just to be suitable for this very purpose.
Of course,artifical photosynthesis already exists,essentially using the same process;photons,chloroplasts,calvin cycle,photosystems 1 & 2,etc.It utilizes the general concept with photoelectrochemistry,so basically just replacing the organic tools with artificial photoelectric cells,which also uses h20 and light.What you are asking is why we have not developed genetically engineered organic matter to produce higher efficiency.As a matter of fact,GMO plant's already exist with immunity,though I have not heard of GMO that catalyzes photosynthetic reactions,and best not,because genetic engineering is still at it's best a new field that is too complex,for example,the general GMO is to incorporate the bacterial enzyme cas9 to cleave away specified DNA to alter an organism's genome,such as inhibiting receptors to cannabinoids,or to fight pests with substances that are not harmful to humans,etc.But it has consequences,such as permanence of that edited genome,so if the organism/plant reproduces,the progeny would also exhibit the same GMO properties.
Photosynthesis is a complicated series of reactions that uses complicated enzymes and such.For example,the enzyme rubisco that changes co2 to energy rich molecules such as glucose,from highly unstable phosphoglycerates.Artifical photosynthesis is quite new,but it also uses the same fuel;co2,h20,and light,not sure if it uses biological nutrients like soil,but the process also uses Nicotinamide adenine dinucleotide phosphate,or NADP+.It is used for anabolic reactions,so it builds up molecules,vice versa are catabolic reactions,which is when enyzmes break down lipids and molecules in metabolism.Albeit I do not know for sure if this molecule has the same purpose in artifical photosynthesis,but for general photosythesis,yes.NADP+ also absorbs electrons for independent and dependent reactions to generate ATP and NADPH,etc.
I hope this simplifies some things.CONCLUSION:we do have artifical photosynthesis,but gmoed photosynthesis may be harmful to a plant's heredity if we damaged it's genome,causing potential harm.
Artifical is quite similar to organic,so I guess you say they are biopanels,using h20,co2,and light.